NEW ORLEANS -

A federal judge overseeing a $4.85 billion settlement with Merck & Co. involving its withdrawn Vioxx painkiller expressed confidence Friday that lawyers have resolved ethical concerns about the agreement.

Some lawyers for Vioxx patients have challenged a provision of the settlement that bars attorneys with clients who participate in the deal from representing others who opt out. That could force lawyers to advise all or none of their clients to accept the agreement.

On Friday, however, U.S. District Judge Eldon Fallon said lawyers have amended the November 2007 pact so that attorneys are directed to exercise their "independent judgment in the best interests of each client individually before recommending enrollment in the program."

"I'm satisfied that nothing in the agreement imposes on a lawyer any impermissible restriction on the practice of law," Fallon told lawyers on both sides of the deal during a hearing in New Orleans.

Tens of thousands of Vioxx users who sued Merck have tentatively signed on to the agreement, leaving both sides confident the deal will go forward.

A total of 57,167 claimants have registered for the settlement program, which Fallon said represents about 95 percent of potential claimants. Merck has said it will withdraw from the agreement unless at least 85 percent of people in different groups of claimants sign on.

A total of 3,065 claimants already have moved on to the next phase and enrolled in the program, said Merck spokesman Kent Jarrell.

"We expect that we will meet and exceed the thresholds required for funding the settlement," Jarrell said following Friday's hearing. "We just don't know when it will occur."