A 16.53 percent stake in National Intergroup has been acquired by Centaur Partners of New York.

The columnist Dan Dorfman in USA Today said Centaur Partners, a New York investor group, had acquired 3 percent of Tambrands.

Among other issues, Goodrich rose 1 3/4, to 66 5/8, in active trading on rumors that the company might be the takeover target of Centaur Partners, an investor group.

Traders said the Ferro Corporation, which rose 2 1/4, to 48 5/8, had no comment on whether Centaur Partners had increased or had a stake in Ferro.

Pennwalt's announcement came two days after Centaur Partners, a New York investment group, said it had purchased 6.5 percent of the diversified Philadelphia company, whose main business is its chemical operations.

Among individual issues, the Ferro Corporation jumped 3 3/4, to 54 3/8, amid continued speculation that the company might be the target of a takeover by Centaur Partners.

Pennwalt is trying to fend off a hostile $850 million bid from Centaur Partners, a New York investment firm.

The company embarked on the restructuring plan as a way of fending off a takeover by Centaur Partners, an investment group that owns 8.6 percent of the company.

The board of the Pennwalt Corporation today rejected a buyout proposal of $100 a share from Centaur Partners, calling the figure "completely unacceptable."

The merger agreeemnt defeated a hostile offer of $110 a share for Pennwalt from Centaur Partners, a group of American businessmen.