Exhibit 99.1

UNION BANKSHARES NET INCOME UP 11% FOR FOURTH QUARTER; 38% FOR 2005

FOR IMMEDIATE RELEASE (Bowling Green, Virginia) — Union Bankshares (NASDAQ: UBSH - News) reports net income for the fourth quarter ended December 31, 2005 of $5.9 million, up 11% from $5.3 million the same quarter in 2004. Earnings per share, on a diluted basis increased from $.60 to $.66, or 10%, over the same time period. Return on average equity for the quarter ended December 31, 2005 was 13.18%, while return on average assets for the same period was 1.29%, compared to 13.13% and 1.27 %, respectively, for the same quarter a year earlier.

For the year ended December 31, 2005 net income increased 38.5% to $24.8 million from $17.9 million for the same period a year ago. Over this same period, earnings per share on a diluted basis increased 33.2% from $2.11 to $2.81. Return on average equity for the year ended December 31, 2005 was 14.49%, while return on average assets for the same period was 1.43%, compared to 12.18% and 1.19%, respectively, for the year ended December 31, 2004. Results for the first four months of 2004 do not reflect the May 1, 2004 acquisition of Guaranty Financial Corporation (“Guaranty”).

On a linked quarter basis (current quarter to most recent quarter) net income declined 14.7% from $6.88 million to $5.87 million for the quarter ended December 2005. This represents a earnings per share decrease, on a diluted basis, of $.12, or 15.4%, for the fourth quarter and is largely attributable to declines in the mortgage segment, customer fraud losses and normal growth and expansion efforts.

As a supplement to accounting practices generally accepted in the United States of America, the Company also uses certain alternate financial measures to review its operating performance. Earnings per share on a cash basis for the quarter ended December 31, 2005 was $.68 as compared to $.62 in the same period a year ago and $.80 for the third quarter of 2005. Cash basis return on average tangible equity for the quarter ended December 31, 2005 was 17.61% compared to 18.32% in the same period a year ago and 20.88% for the third quarter of 2005.

“It is a pleasure to report annual earnings results of $2.81 per share which represents a 33% increase over the prior year, said G. William Beale, Union Bankshares President. Our shareholders should be pleased with the earnings results and total shareholder return achieved in 2005. Management positioned the Company to respond favorably to rising interest rates and, both the Company and our shareholders have benefited. We anticipate that 2006 will be a

challenging year as we focus on asset growth and margin retention, as well as the integration of Prosperity Bank into our banking family.”

Segment Information

Fourth quarter net income for the community banking segment was $5.9 million, an increase of $965 thousand or 19.7% from $4.9 million in the fourth quarter of 2004. This increase was driven by margin expansion of $2.5 million, or 16.3% to $17.9 million. Increased credit quality resulted in a lower provision for loan losses of $245 thousand. Other noninterest income increased $202 thousand, or 6.8%, principally as a result of increased debit card income, ATM fees and other operating income. Other noninterest expense increased $1.6 million, or 14.5%, principally as a result of increases in salaries and benefits and other operating losses that included losses related to customer fraud activity.

Fourth quarter net income for the mortgage banking segment was $7 thousand, a decrease of $388 thousand from $395 thousand in the fourth quarter of 2004. Contributing to the decline were lower production volumes from $136.3 million to $115 million, or 18.5%. Higher funding costs compared to the prior quarter a year ago also contributed to lower income. Moreover, the Washington metro area has seen a slowdown in purchase activity this quarter compared to last year’s same quarter. The mortgage segment also incurred costs during the fourth quarter to relocate to another office, as well as investments in technology to improve loan origination and reporting.

For the year ended December 31, 2005, the community bank segment net income increased $7.2 million from $16.5 million to $23.7 million. Margin expansion of $14.8 million, lower loan loss provisions of $982 thousand, increased noninterest income of $1.1 million, offset by $5.8 million increase in noninterest expenses drove the annual net income increase.

For the year ended December 31, 2005, the mortgage segment reported net income of $1.1 million, a decline of $281 thousand, or 20% from $1.4 million in 2004. Despite production volumes increasing from $496.2 million to $556.8 million, or 12.2%, unit levels increased only 1.2% on loan products that were less profitable than ones in the prior year. Due to customer demand, these less profitable loan products became a larger percentage of production volume during 2005. Additionally, a flattening yield curve has put pressure on loan sale profitability.

On a linked quarter basis, community banking segment net income decreased $449 thousand or 6.3% from $6.3 million for the quarter ended September 30, 2005 to $5.9 million for the quarter ended December 31, 2005. Margin expansion continued, increasing $329 thousand and the provision for loan losses was $156 thousand lower than the prior quarter. These improvements were offset by increased operating expenses of approximately $727 thousand, increased salaries and benefits of $426 thousand and lower non-interest income of $146 thousand, which drove the quarterly decline in income of approximately $449 thousand after tax.

On a linked quarter basis, net income for the mortgage segment during the fourth quarter of 2005 decreased to $7 thousand from $567 thousand a quarter earlier. Lower production volumes, increased funding costs and tighter profit margins were key contributors to this decline.

Net Interest Income

Net interest income on a fully tax equivalent (FTE) basis increased $2.4 million, or 14.4% to $18.6 million for the quarter as compared to the same quarter in 2004. Average earning assets increased $124.4 million, or 8.1%, funded largely by total average interest-bearing deposit growth of $110.8 million, or 10.4%. Additionally, average demand deposits contributed $26.8 million to further fund loan demand and represented an 11.5% increase over the prior year’s fourth quarter. These factors, coupled with increased yields on loans to 6.98%, from 6.12%, were partially offset by an increased cost of funds on deposits to 2.56%, from 1.97% and moved the net interest margin up by 24 basis points to 4.47%. Of the $124.4 million in average earning asset growth (primarily in the commercial and construction portfolios), approximately 21.5% was funded by noninterest-bearing deposits, positively contributing to the increased margin.

For the year ended December 31, 2005, net interest income (FTE) increased $14.1 million or 24.7% over the same period a year ago. Yields on average earning assets increased 57 basis points, or 9.6%, on growth of $207.1 million in interest earning assets. Yields on interest-bearing liabilities increased 29 basis points, or 13%, on growth of $155.2 million in interest-bearing liabilities. The remaining margin improvement was due to growth of demand deposit accounts of $49.1 million.

On a linked quarter basis net interest income (FTE) grew by $185 thousand, or 1.0% for the quarter ended December 31, 2005 from the quarter ended September 30, 2005. This translated into a six basis point decline in the net interest margin during the quarter, from 4.53% to 4.47%. This is due to cost of funds increasing by 20 basis points to 2.78% and yields on earning assets increasing by 11 basis points to 6.73%. Contributing to this margin pressure were increased volumes of certificates of deposit greater than $100 thousand as well as a lower reliance on non-interest bearing demand deposits when compared to the prior quarter.

Since June 2004, we have experienced an increase in the Federal Funds target at each Federal Reserve Board Open Market Committee (“FOMC”) meeting, benefiting the Company due to its asset sensitivity. Based upon its asset liability management modeling, management anticipates the Company’s net interest margin will moderate at current levels. In an effort to protect its improved net interest margin and reduce its interest rate sensitivity, management will continue to closely monitor its interest rate risk as the FOMC nears the anticipated end of the current tightening cycle.

Asset Quality

The Company’s asset quality remains good as reflected in the $982 thousand decrease in provision for loan losses, from $2.2 million for the year ended December 31, 2004 to $1.2 million for the year ended December 31, 2005. Contributing to the year to year decline in the provision for loan losses has been improved credit quality and the payout of a number of low credit quality loans. On a linked quarter basis, the provision for loan losses decreased $155 thousand from $430 thousand for the quarter ended September 30, 2005 to $275 thousand for the quarter ended December 31, 2005. This change is largely attributable to an increase in the specific reserve occurring during the third quarter.

Management maintains a list of loans that have a potential weakness that may need special attention. This list is used to monitor such loans and is used in the determination of the sufficiency of the Company’s allowance for loan losses. At December 31, 2005, non-performing assets totaled $11.3 million, including a single credit relationship totaling $10.8 million in loans.

The loans to this relationship are secured by real estate (two assisted living facilities and other real estate). Based on the information currently available, management has allocated $1.3 million in specific reserves to this relationship. The Company entered into a workout agreement with the borrower in March 2004. Under the terms of the agreement, the Company extended further credit secured by additional property with significant equity. The Company continues to have constructive dialogue with the borrower towards resolution of the affiliated loans; however, bankruptcy filings by some affiliates of the borrower have delayed the accomplishment of targeted actions. The Company continues to anticipate that this workout will ultimately result in a reduction of the Company’s overall exposure to the borrower.

Net charge-offs were $81 thousand for the quarter compared to $153 thousand in the same quarter last year. Net charge-offs were $440 thousand for the year ended December 31, 2005 compared to net recoveries of $671 thousand for the same period a year ago. Recoveries during the year were lower than last year as the Company completed, in 2004, the recovery of principal on a large loan charged-off in prior years. For the year ended December 31, 2005 approximately $311 thousand was collected in foregone interest on the aforementioned credit and recorded in interest income.

Noninterest Income

Noninterest income for the fourth quarter of 2005 decreased by $388 million to $5.9 million, or 6.2%, compared to the same quarter in 2004. This change was principally due to a decrease in gains on sales of mortgage loans of $586 thousand, or 18%, partially offset by an increase of $75 thousand in other service charges and an increase of $81 thousand in other operating income. Mortgage loan production for the fourth quarter of 2005 totaled $115.0 million as compared to $136.3 million in the fourth quarter of 2004. This 18.5% decrease in production and tighter pricing margins were the primary drivers of decreased gains on sales of mortgage loans. The increase in other service charges was driven primarily by $101 thousand increase in income related to debit card and ATM transactions and $43 thousand from rebates from the sale of checks. These increases were offset by a $54 thousand decline in letter of credit fees and a $42 thousand decline in brokerage commissions from our investment company.

On a linked quarter basis, noninterest income decreased $1.4 million or 19.6%. This change was principally due to decreases in gains on sales of mortgage loans of $1.3 million, or 32.1%. Decreases in other operating income and service charges on deposits represented $74 thousand and $51 thousand, respectively. Mortgage loan production decreased $57.2 million, or 33%, from the prior quarter and caused most of the decrease in the gain on sale of mortgages. Service charges on deposit accounts decreased primarily as a result of reduced overdraft and return check charges.

For the year ended December 31, 2005, noninterest income increased $2.2 million, or 9.5%, to $25.5 million. Gains on sale of mortgages, other service charges and fees and other operating income offset by service charges on deposit accounts and lower investment security gains contributed to the increase in noninterest income. Driving the increase were gains on the sale of mortgages which grew to $13 million for the year and represented a $1.1 million, or 9.6%, increase over the same period a year ago. Mortgage loan production increased 12.2%, or $60.6 million driving the increased gains on loan sales. Additionally, other service charges and fees increased $929 thousand, or 27% to $4.4 million. This increase is principally due to income received from debit cards, letters of credit, exchange fees and brokerage commissions from our investment company. Service charges on deposit accounts decreased $36 thousand, but contributed $6.8 million for the year ended December 31, 2005. Other operating income

increased $197 thousand or 17.4%, including income from Johnson Mortgage Company of $92 thousand and an increase in cash surrender value of bank owned life insurance of $71 thousand.

Noninterest Expense

Noninterest expense during the fourth quarter of 2005 increased $1.5 million, or 11%, from the same quarter in the prior year. This includes an increase of $785 thousand in salaries and benefits, $128 thousand in occupancy expense, $133 thousand in furniture and equipment expense and $485 thousand in other operating expenses. The increase in salary and benefits was due to the opening of additional branches, hiring support staff, as well as compensation adjustments. Other factors contributing to this increase were increased profit sharing expenses and health insurance expense. A one-time charge of $64 thousand related to the acceleration of vesting of stock options also contributed to this increase. These increases were offset by decreases in commissions in the mortgage segment, as well as less reliance on contract labor and overtime pay. The increase in occupancy and furniture and equipment expense was also due primarily to new branch openings. Increases in other operating expenses were principally related to customer fraud losses which increased by $365 thousand. Other notable increases were directors’ fees, professional services and marketing which represented approximately $271 thousand of the increase. Offsetting this increase was $134 thousand in conversion expenses in 2004 from the acquisition of Guaranty with no additional expense in 2005.

On a linked quarter basis noninterest expense increased $679 thousand or 4.6%. Other operating expenses increased $733 thousand compared to the prior quarter. This change includes an increase in other losses of $391 thousand due principally to customer fraud activity. Marketing and advertising expense increased $166 thousand largely as a result of the media campaign that promoted our corporate shared values. Salaries and benefits decreased $155 thousand from the prior quarter principally due to declines in commissions of $490 thousand in our mortgage segment as a result of decreased mortgage loan production. This large decrease was offset by an increase in awards and incentives and higher employee replacement costs. There was also a one- time charge of $64 thousand related to the acceleration of vesting of stock options. Furniture and equipment expense, data processing and occupancy costs also increased as a result of the Company’s normal growth and expansion efforts.

For the year ended December 31, 2005, noninterest expense increased $7 million, or 13.8% from a year ago. Driving the increase were salary and benefits expenses of $4.4 million, or 15.2%. Occupancy and furniture and fixture expenses increased $720 thousand, or 21.0% and $482 thousand, or 14.0%, respectively. Lastly, other operating expenses increased $1.4 million, or 9.3%. The increase in salary and benefits is due to the opening of additional branches, hiring support staff, increased commissions in the mortgage segment related to increased loan production, as well as compensation adjustments. Other contributing factors include profit sharing expenses and health insurance expense. Occupancy and furniture and fixture expense increases correlate to additional branch openings and other operating costs associated with maintaining our branch network.

Of the $1.4 million in increased operating expenses, approximately $527 thousand resulted from increased courier services, internet activity and communication activity with customers, $465 thousand in other bank losses related primarily to customer fraud activity mentioned above, $304 thousand from media and advertising campaigns, $213 thousand related to amortizing additional core deposit intangibles related to the Guaranty acquisition, $196 thousand from increased directors’ fees as the compensation structure was modified in May 2005, $181 thousand was from

increased ATM processing and placement of additional ATM machines within our existing footprint. An additional $112 thousand was due to data processing costs related to increased activity in the bankcard department. Other expense increases relate to training and seminars of $100 thousand, as well as mileage reimbursement of $75 thousand. These expenses were offset by lower data processing costs of $445 thousand and conversion charges of $326 thousand both relating to the Guaranty acquisition in 2004.

Balance Sheet

Net loans were $1.35 billion and $1.25 billion at December 31, 2005 and 2004, respectively. Current quarter to prior quarter growth totaled approximately $13 million or an increase of 1.0% predominately within the commercial real estate, commercial construction, and equity line portfolios. The rising interest rate environment has improved the Company’s yield on earning assets. Total deposits increased $24 million during the fourth quarter of 2005 to $1.46 billion and represented increased growth compared to the prior quarter. Growth of $50 million was experienced in large certificates of deposit (those greater than $100 thousand) offset by declines in money market account and savings accounts of $9.2 million and $2 million, respectively. Additionally, declines were experienced in noninterest bearing deposits of $10.8 million compared to the prior quarter.

At December 31, 2005 total assets were $1.82 billion, up 8.3%, or approximately $153 million from $1.67 billion a year earlier. Securities increased to $246.0 million compared to $233.5 million for the same period. Total assets have increased $33.0 million from $1.79 billion at September 30, 2005 to $1.82 billion at December 31, 2005. Securities increased $18.6 million from $227.4 million to $246.0 million. The Company’s capital position remains strong with an equity-to-assets ratio of 9.83 %.

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ABOUT UNION BANKSHARES CORPORATION

Union Bankshares is one of the largest community banking organizations based in Virginia, providing full service banking to the Central, Rappahannock, Williamsburg and Northern Neck regions of Virginia through its bank subsidiaries, Union Bank & Trust (32 locations in the counties of Albemarle, Caroline, Chesterfield, Fluvanna, Hanover, Henrico, King George, King William, Nelson, Spotsylvania, Stafford, Westmoreland and the Cities of Charlottesville and Fredericksburg), Northern Neck State Bank (9 locations in the counties of Richmond, Westmoreland, Essex, Northumberland and Lancaster), Rappahannock National Bank in Washington, Virginia and Bank of Williamsburg (3 locations in Williamsburg and Newport News). Union Bank & Trust also operates a loan production office in Manassas. In addition to banking services, Union Investment Services, Inc. provides investment advice to our clients and Mortgage Capital Investors provides a full line of mortgage products. The Bank of Williamsburg also owns a non-controlling interest in Johnson Mortgage Company, LLC. Additional information is available on our website at www.ubsh.com. The shares of Union Bankshares Corporation are traded on the NASDAQ National Market under the symbol “UBSH”.

The Company recently announced it had a signed a definitive agreement to which Union Bankshares will acquire Prosperity Bank & Trust, a nearly $130 million in assets company

operating three offices in Springfield, Virginia. It is anticipated that, subject to regulatory and shareholder approvals, the transaction will close in the second quarter of 2006.

FORWARD-LOOKING STATEMENTS

This press release may contain “forward-looking statements,” within the meaning of federal securities laws that involve significant risks and uncertainties. Statements herein are based on certain assumptions and analyses by the Company and are factors it believes are appropriate in the circumstances. Actual results could differ materially from those contained in or implied by such statements for a variety of reasons including, but not limited to: changes in interest rates; changes in accounting principles, policies, or guidelines; significant changes in economic conditions; significant changes in regulatory requirements; and significant changes in securities markets. Consequently, all forward-looking statements made herein are qualified by these cautionary statements and the cautionary language in the Company’s most recent Form 10-K report and other documents filed with the Securities and Exchange Commission. Union Bankshares Corporation does not undertake to update forward-looking statements to reflect circumstances or events that occur after the date the forward-looking statements are made.

Key Financial Data

($ in thousands)

In management’s opinion, cash basis earnings are useful to investors because by excluding non-operating adjustments stemming from the consolidation of our organization, they allow investors to see clearly the combined economic results of our multi-bank company. These non-GAAP disclosures should not, however, be viewed in direct comparison with non-GAAP measures of other companies.

UNION BANKSHARES CORPORATION AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

(dollars in thousands, except share information)

UNION BANKSHARES CORPORATION AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited)

(dollars in thousands, except per share amounts)