Kenneth J. Martin, Wyeth chief financial officer, told stock analysts in a conference call that the $2 billion was the minimum needed to cover settlement claims, heart valve and PPH opt outs and legal fees.

Of the total amount set aside for diet drugs, $3.6 billion remained as of Sept. 30, according to a Form 8-K filed today with the U.S. Securities and Exchange Commission. Wyeth said that may not be enough to resolve tens of thousands of matrix claims within the settlement and notices from thousands more former diet drug users of their intent to opt out of the settlement and proceed to trial.

"It is not possible to predict the ultimate liability of the Company in connection with its diet drug legal proceedings," the 8-K says, including its effect on cash flow, dividends, capital expenditures and debt repayment.

Wyeth also reported initial results of the controversial 100 percent audit program instituted by the Settlement Trust and approved by the diet drug MDL court: Of 820 completed claims audits, 301, or 36 percent, were deemed payable at amounts claimed or at lower amounts. The company could not say if those audit results were a representative sample of audited claims.

Wyeth also reported that the trust has adopted a program to prioritize the handling of claims, with highest priority given to those that "are least likely to be illegitimate."

Wyeth warned that even if the trust's Integrity Program, aimed at rooting out unsubstantiated claims, makes substantial progress, significant numbers of claims might satisfy eligibility criteria. "If so, matrix claims found eligible for payment after audit may exceed the $3.75 billion cap of the settlement fund," it said.

If the settlement fund is exhausted, Wyeth said claimants may opt out under the settlement's Sixth Amendment, unless the company elects to pay the benefits. As of Sept. 24, Wyeth said the trust has received 108,000 claims forms.

Martin said Wyeth is more convinced that it needs to contest questionable claims. He said new suits are being moved to federal court.

In an unusual move, Wyeth filed developments about the litigation in an 8-K instead of waiting to add them to the next 10-K, which usually is filed a month after earnings are announced.

The $2 billion charge contributed to a $426 million third-quarter loss. As of 1:30 p.m. today, Wyeth's stock price fell from $44.40 a share to $42.40, a loss of $3.40 per share and 7.42 percent in value.