Seagram has upped its stake in Time Warner Inc. to 8.1% for a total investment of $ 1.1 billion.The Montreal-based company first bought into Time Warner last May, picking up a 5.7% stake for $ 700 million. Seagram execs have said the company will buy up to 15% of the shares of the New York-based entertainment firm. Seagram makes numerous beverages, including Chivas Regal, owns fruit-juice producer Tropicana Products and has a minority stake in chemical giant E.I. du Pont de Nemours & Co. Seagram has been making the purchases on the open market and now has just over 30 million Time Warner shares. Power Corp., another Montreal-based company, also bought into Time Warner this year, paying $ 100 million for a 1% stake. Seagram and Power are connected by directors who sit on both boards.