Fund raisers have spent months pushing Congress to extend a tax break that allows older donors to channel money from their individual retirement accounts to charity.

But now that the extension has become law as part of the federal financial bailout measure, fund raisers have less reason to be overjoyed: Since many account holders suffered losses in the stock market, older Americans may be less inclined to give through the retirement accounts.

Still, Timothy Prosser, vice president of institutional trust consulting at TIAA-CREF, told planned-giving specialists gathered at the annual meeting of the National Committee on Planned Giving, in Denver, that charities can still benefit from the tax incentive.

The best prospects, he said, are donors who do not itemize their tax returns or are subject to adjusted gross income tax limitations, as well as donors who want to make large gifts and don’t have other assets.

In the past, he noted, many retirement account holders gave to charity to satisfy federal requirements that they spend a small percentage of the money in the accounts annually once they reach age 70½. But now the minimum sum they must spend will be much smaller because of the losses sustained in the stock market, so far less will probably flow to charity.

The provision could become an even weaker incentive soon: Both Barack Obama and John McCain have proposed reducing or waiving the required minimum distribution.