TORONTO, AUG. 2 -- The owner of the Montreal Expos has set a Sept. 1 deadline for a Quebec investor to come forward with a serious purchase offer, after which he will start talking with prospective buyers in the United States, according to club officials.

Owner Charles Bronfman, confirming an asking price of about $100 million (roughly 85 million U.S. dollars), says that although he would prefer to see the club remain in Montreal it would be "nonsensical" to delay the sale process indefinitely if he cannot find a local buyer.

With no serious local offers since Bronfman first disclosed late last year that he was interested in selling, Expos President Claude Brochu has been prowling the corporate boardrooms in Quebec looking for a buyer.

One prospect, Molson Breweries, which owns the Montreal Canadiens in the National Hockey League, has said it is not interested in getting into baseball.

Brochu, while declining to discuss specific moves that would be taken if the deadline is not met, made it clear that offers from potential U.S. buyers would be considered. "People are well aware of the implications," he said in Montreal. "We don't have to draw them a picture."

Richard Griffin, an Expos spokesman, said that although attendance at Olympic Stadium has steadily dwindled -- only 939,850 have gone through the turnstiles after 51 games -- the team would be sold as a money-making franchise, largely because of television broadcasting fees.

Last season, even though they seriously contended for the division title most of the season, they attracted only 1.78 million spectators, a disappointing turnout at a time when baseball attendance elsewhere was on the increase.

For most of his 21 years of ownership, Bronfman, head of the Seagram distillery empire, has absorbed hefty Expos losses, but the club's revenues have reportedly doubled to about $50 million in the last four years because of concessions and the television payouts. Bronfman paid $10 million for the franchise is 1969.

About a dozen potential American buyers are said to have expressed interest in the Expos, including the owners of the Class AAA Bisons in Buffalo, N.Y., and entrepreneurs in the Tampa-St. Petersburg area.

Griffin said he was not aware of any offers made so far by investors in Washington, whose Senators moved to Texas in 1972.

Any attempt by a U.S. group to purchase the Expos and move it to another city would have to be approved by Commissioner Fay Vincent and the league's clubowners.

Currently in third place in the National League East, the Expos have been playing to steadily thinning crowds at home, partly because many of the team's most popular players have wanted out and have been traded to U.S. teams.

Moreover, the word around the league is that free agents generally prefer to stay away, partly because of Canada's relatively high income tax, but also because many players regard Montreal as foreign.