(Reuters) - Allergan Plc (>> Allergan, Inc.) Chief Executive Brent Saunders said on Monday the company expects to close the $40.5 billion (£28 billion) sale of its generic medicines portfolio to Teva Pharmaceutical Industries Ltd (>> Teva Pharmaceutical Industries Limited) in a matter of weeks, opening the door for new acquisitions.

While Allergan needs the Teva transaction to close before pursuing new targets, "the good news is we are weeks away from that happening," Saunders said after a presentation at the UBS Global Healthcare Conference in New York.

Reuters reported earlier this month that Israel-based Teva was finalising up to $2 billion in asset sale agreements to win antitrust clearance for its purchase of the Allergan products.

Saunders said Teva and the U.S. Federal Trade Commission were working "very constructively" on the issue and that a planned closing of the deal next month is still the most likely scenario.

He added that while large-scale, "transformational" deals are not currently on the table, Ireland-based Allergan will be able to consider transactions worth multiple billions of dollars.

The FTC has blocked several major transactions this year, prompting concerns among investors that there could be problems closing the Allergan-Teva deal.

Pfizer Inc's (>> Pfizer Inc.) deal to buy Allergan for $160 billion was derailed last month by new U.S. Treasury rules that targeted its anticipated tax benefits.

By Caroline Humer