James River Bankshares (JRBK) said Monday it will merge with First Virginia Banks in a stock swap valued at $107.1 million. James River's stock soared 52.9% to a 52-week high on the news.

At midday, shares of James River were up $7.88 to $22.75 on the

Nasdaq

, while First Virginia's shares were down 13 cents, or 0.3%, to $45.97 on the

New York Stock Exchange

.

The agreement calls for First Virginia to exchange 0.51 shares of its stock for each of James River's 4.6 million outstanding shares. Based on First Virginia's Friday closing price of $46.10, that places a value on James River of roughly $23.51 a share.

First Virginia will issue 2.3 million shares to James River shareholders in a tax-free stock exchange. Stockholders can exchange up to 40% of James River shares for $24 each in lieu of First Virginia stock.

The four James River banks will merge with existing First Virginia member banks, and the James River's directors will become members of the boards of the merged banks.