International investor Alan E. Clore has cast a shadow over the planned merger of A.H. Robins Co. with Rorer Group Inc. by applying for U.S. government clearance to buy up to 25 percent of Rorer's common stock and saying he may seek control of the company.

Clore notified the Securities and Exchange Commission Tuesday that he already beneficially owns 12.2 percent of Rorer stock -- 2,672,000 shares valued at more than $140 million.

He told the SEC that he is seeking permission from the Justice Department and the Federal Trade Commission to buy up to one-fourth of the shares outstanding.

The SEC filing led financial analysts to speculate as to Clore's intentions because he left the door open to an attempt to take over Rorer; to selling the stock later on, or to an effort to block the merger with Robins on grounds the deal would dilute the value of his Rorer shares.

Clore, a British citizen who is the son of the late Sir Charles Clore, a British retailing magnate, could not be reached at his home in Geneva. Stephen E. Jacobs, his lawyer at Weil Gotshal & Magnes in New York, did not return phone calls.

A Rorer spokesman in Fort Washington, Pa., declined to comment, saying, "We do not know what his intentions are," and that the company is not interested in being taken over.

"The merger agreement with Rorer does contain a provision that stipulates if there is a change in control of Rorer, A.H. Robins may, and I emphasize may, terminate the agreement," Robins spokesman Roscoe Puckett told The Associated Press.

"However, there has not been a change in control at this point," Puckett said. "If and when a change occurs, A.H. Robins will address that situation.

"In the meantime, the company is proceeding on the assumption that its amended plan of reorganization will be confirmed by the bankruptcy court and that the proposed merger with Rorer will be consumated."

Last Friday in Richmond, Robins, which is in its third year of voluntary bankruptcy, filed its amended plan for financial reorganization, which is based on the planned $2.6 billion merger with Rorer.

Under the plan, the merged company would set up trusts to pay up to $1.75 billion to satisfy valid claims filed by tens of thousands of victims of the Dalkon Shield, the intrauterine contraceptive device Robins sold in the 1970s.

Whether the plan will go into effect is uncertain. The Dalkon Shield Claimants' Committee said that $1.75 billion may be insufficient. The disclosure statement said, by contrast, that if the U.S. Bankruptcy Court, after a November hearing, rules that the total value of the claims exceeds $1.75 billion, "Rorer may not acquire Robins and therefore this plan will not go into effect ... "

The uncertainty was heightened by the Clore filing, which raised the possibility of a struggle for control of Rorer that could last for months.