Pennzoil Co. said that 95 percent of Facet Enterprises Inc.'s common stock has been tendered into its $32-a-share cash offer for the filtermaker.

The $250 million offer expired at 11 p.m. Thursday, and more than 5.7 million Facet shares were tendered by the deadline, the oil giant said.Tulsa-based Facet, which also has operations in Salt Lake City employing about 278 people, sought Penn-zoil as a "white knight" to help fight off hostile bidder Prospect Group Inc.

The Facet board rejected a $27.50-a-share offer from Prospect and instituted anti-takeover provisions. Prospect dropped its $199 million bid shortly after Pennzoil came on the scene.

Facet is Houston-based Pennzoil's first acquisition since it received $3 billion in cash from Texaco Inc. as settlement in their four-year legal dispute over control of Getty Oil Co.

Pennzoil officials have said, however, that the Facet purchase is not part of their strategy for using that money. Pennzoil officials will meet next month to discuss further acquisitions.

Pennzoil, Facet's largest customer, has said it will operate the company from its current headquarters as a separate entity.

As part of the deal, Pennzoil reportedly will assume $50 million in Facet debt, which resulted mostly from its $67 million acquisition of Purolator Products Inc. last year.

Facet President James Malone said the company would be in a better position to accelerate its expansion plans under Pennzoil control.

Facet is considering acquisitions - in the aviation and auto filter businesses as well as in the medical and food filtration businesses - to help boost its annual revenue from the current $350 million to $1 billion by 1990, Malone said.