A.H. Robins Co.'s proposal to merge with a French pharmaceutical company and emerge from bankruptcy court protection ran into further resistance yesterday amid indications that the bidding war for the company has resumed.

Robert M. Miller, the attorney for a committee representing holders of about 60 percent of Robins stock, said in an interview yesterday that the committee has told the French company, Sanofi S.A., that its bid for Robins is unacceptable and that "they had to improve the offer monetarily."

"Right now, the {Sanofi} plan is a lame-duck plan," Miller said.

Miller said the committee met Tuesday with representatives of Sanofi and of two American drug manufacturers who also have bid for Robins -- American Home Products Corp. and Rorer Group Inc.

"All three of the bidders indicated that they were willing to improve and enhance their proposals in order to obtain our endorsement," Miller said. He would not elaborate.

Lawyers for the thousands of women who claim they were injured by Robins' Dalkon Shield contraceptive device have sharply criticized the company's proposal to be taken over by Sanofi. The opposition of Miller's committee casts further doubt on the chances that Robins can obtain court approval for the Sanofi plan without a bitter -- and possibly unsuccessful -- fight, according to lawyers and other sources involved with the case.

Either the Dalkon Shield claimants or the outside shareholders committee could press Robins to change its mind. Short of that, they could seek permission from the Richmond court overseeing the case to submit a competing plan from a different bidder.

"For anyone to believe that what Robins and Sanofi offered the other day is where this case is going would be a little naive," said Stanley K. Joynes, the lawyer for future Dalkon Shield claimants.

Despite the mounting opposition to the company's plan, a Robins spokesman said the company expected to file a new plan of reorganization last night with the U.S. Bankruptcy Court in Richmond. The plan incorporates the Sanofi offer and the establishment of a $2.475 trust fund for Dalkon Shield claimants.

Sanofi executives were traveling to New York yesterday to appear at a news conference this morning with Robins executives.

Robins has been operating under federal bankruptcy court protection since August 1985. Any proposal to reorganize the company and allow it to emerge from bankruptcy is subject to a vote by shareholders, claimants and other Robins creditors, as well as approval by U.S. District Judge Robert Merhige Jr., who is overseeing the case.

Robins accepted Sanofi's bid last Friday after receiving three offers for the company. Each of the bidders has agreed to set up the trust fund for claimants, as ordered by the judge, but observers say the complex stock transactions involved in each offer make it difficult to compare the three bids.

According to lawyers and other observers, the Robins board appeared to be attracted to the Sanofi bid in large part because of greater guarantees that the current management would retain a major role in running the company as a free-standing subsidiary after merger. The Robins family controls 41 percent of the company's stock.

However, lawyers for the claimants have criticized the proposed acquisition on the grounds that it would not guarantee prompt payment of claims to Dalkon Shield claimants. And lawyers for the nonfamily shareholders say their clients would not receive enough under money under the Sanofi plan, which offers $600 million in notes and stock for 58 percent of Robins' stock. The other two offers are for 100 percent of the stock.

Yesterday, one of the outside shareholders, a group led by New York investor Michael H. Steinhardt, revealed in a filing with the Securities and Exchange Commission that as matters stood on Dec. 31, it would have supported the Rorer proposal.

Spokesmen for American Home Products and Rorer Group said yesterday that the companies remain interested in acquiring Robins and are continuing discussions with various parties. American Homes is proposing to exchange $600 million of its stock for Robins stock, while Rorer is offering stock worth roughly $720 million, based on yesterday's closing stock price of $21.75.