GAF Corp. has increased its Union Carbide holding to 7.1% of Union Carbide's outstanding shares from 5.6%, a GAF spokesman said Tuesday.
Mark Kappel of Fred Rosen Associates, a public relations agency representing GAF, said GAF now holds about 5 million of Union Carbide's 70.4 million outstanding shares.
A GAF disclosure earlier this month that it had acquired 5.6% of Union Carbide's shares fueled speculation that GAF might be attempting to acquire all or part of the troubled chemical manufacturer.
GAF said in its filing that it bought the Union Carbide stock because it presented "an attractive investment opportunity" and that, in doing so, GAF had considered "the possibility of a business combination between GAF and Union Carbide."
But it added that it "has no present plans or proposals with respect to Union Carbide that relate to or would result in any extraordinary transaction."
Union Carbide stock was up 25 cents a share to $54.75 in trading on the New York Stock Exchange. GAF was down 12.5 cents at $32.125
GAF is a Wayne, N.J.-based maker of chemicals and building materials. It earned $56.7 million on sales of $731.3 million last year. Samuel J. Heyman took control of GAF in December, 1983, in a bitter proxy fight.
Union Carbide is one of the nation's largest chemical concerns and recorded $9.5 billion in 1984 revenue.
Wall Street analysts have suggested that GAF might be interested in buying part or parts of the troubled chemical company that relate to GAF's own business.
They also have suggested that GAF might not have the cash to acquire more than 10% of Union Carbide without outside help.