Seagram Co. Ltd., the giant Canadian distiller that has lost several merger battles this year, announced today that it wants to buy back up to 5 million of the 35 million shares of its outstanding stock.

Seagram, which does most of its business in the United States, said it would pay $60 a share for the stock, $8.50 more than Seagram's closing price Monday. The company's stock did not trade today, in anticipation of the announcement. Seagram requested the trading halt. If Seagram buys the full 5 million shares, it will pay about $300 million to its shareholders.

Last summer the distiller spent $2.6 billion in a free-wheeling, three-way battle to acquire Conoco Inc., the nation's ninth-biggest oil company. It failed to gain control of Conoco, but in the process became the single largest shareholder in E.I. du Pont de Nemours, the giant chemical company that won the Conoco prize for about $7.5 billion.

It was one of the most bitter and by far the most costly takeover battle in business history. Mobil Corp. was the other losing entrant in the Conoco derby.

When Du Pont won the fight for Conoco, Seagram exchanged the Conoco stock it had acquired for 47.5 million shares of Du Pont, about 20 percent of the chemical giant's outstanding stock. Last week, Du Pont and Seagram reached an agreement that created ties between the two companies but ensured that Seagram would not make an effort to take over the Delaware concern.

Although Du Pont made no formal declaration of its reasons for buying back up to 14.25 percent of its outstanding stock, a company spokesman said Seagram stock has been selling well below the book value of the company and that by repurchasing outstanding shares, the company could help ensure that the price of Seagram's stock would be more in line with its intrinsic value.

According to the spokesman, the book value of Seagram on July 31 was about $77.75 a share.

The Bronfman family, which runs the company and controls about 34 percent of the outstanding stock, does not intend to sell any of its shares under the tender offer, which Seagram said will begin Wednesday. It will expire at midnight Nov. 5.