Two Richmond companies, Ethyl Corp. and United Virginia Bankshares Inc., have split their stocks two for one.

UVB, holding company for the 187-branch United Virginia Bank, said yesterday the split would be effective June 3 if approved by shareholders at their meeting April 22. The board also wants to increase the number of common shares from 10 million to 25 million and of preferred shares from 1 million to 2 million.

The bank increased its quarterly dividend on common shares by 14 percent to 64 cents a share, payable April 30 to owners of record April 11.

In addition to its split Thursday, Ethyl called for redemption of its cumulative second preferred stock, $4 convertible Series B.

Directors also increased the quarterly dividend on common stock to 42 1/2 cents from 37 1/2 cents.

Ethyl is a diversified, high-technology producer of performance and specialty chemicals, plastics and aluminum. It purchased the profitable First Colony Life Insurance Co. last year.

The stock split will be a 100 percent stock dividend, payable April 11 to holders of record March 22. The new dividend will be payable April 1 to holders of record March 14.

The board also voted to recommend doubling the number of authorized common shares to 100 million.

At the end of last year, Ethyl had 18.55 million shares of common and 1.22 million shares of $4 second preferred stock outstanding. Ethyl last split its stock two for one in 1977.

Yesterday, 27,600 shares of Ethyl traded on the New York Stock Exchange, closing up 1 1/2 at 40. Ethyl gained 1 1/4 the day before. UVB closed up 1/2 at 46 1/8 in over-the-counter trading.