ST. LOUIS - Anheuser-Busch Cos. Inc. plans to buy 20 million shares of its stock, a purchase worth more than $1 billion at current prices.

When completed, the purchase would amount to about 7 percent of the company's common stock.

The company will pay for the stock out of earnings and possibly by borrowing, a company spokesman said.

When a company buys its own stock, it typically causes the price to strengthen. Then remaining shareholders own a larger portion of the company, as the number of publicly held shares decreases.

Anheuser-Busch's stock rose $1.25 a share Wednesday to close at $55.75. Over the last year, it has traded for as much as $62 and as little as $48 a share.

No timetable for the stock purchase has been set. A program to buy 15 million shares was authorized in June 1988, and company officials say it's about 75 percent complete.