Shares of Wyeth ( WYE) jumped Tuesday after the company confirmed that it is negotiating to settle many outstanding claims relating to the withdrawn diet-drug cocktail known as fen-phen. The company's stock climbed $1.99, or 4.7%, to $44.27, coming close to its 52-week high of $44.70, after Wyeth confirmed that it is talking to attorneys for plaintiffs who had declined to participate in a national settlement involving the diet drugs Redux and Pondimin. The negotiations were first disclosed in Tuesday's edition of The Wall Street Journal. Wyeth said Tuesday that it is talking to lawyers about a settlement process for these plaintiffs, which, by one estimate, include more than 60,000 people who didn't participate in a national class-action settlement in 1999. "This is a promising development, but many complex issues remain to be resolved," said Lawrence V. Stein, general counsel for Wyeth, in a prepared statement. He said the company "will continue to defend itself in the ongoing litigation until final settlements are reached." Wyeth has set aside reserves of some $16.6 billion to pay plaintiffs who allege the diet drugs caused heart damage. Tuesday's announcement is unrelated to Wyeth's report last week that the company supports an updated revision of the class-action settlement that would deal with "the least serious but most numerous claims" in the settlement, the company said. Wyeth provided few details on the negotiations involving plaintiffs who are not covered by the national settlement. The company said its attorneys and plaintiffs' lawyers have filed a motion with U.S. District Court in Philadelphia "seeking a stay in proceedings in certain pending diet drug cases." The Journal said lawyers representing 11,000 cases have agreed to the new settlement process for cases outside the scope of the national diet-drug settlement.