Gary Gensler's term as chairman of the U.S. agency writing regulations required by the Dodd-Frank Act for the global swaps market ends tomorrow. All the same, his ability to craft rules for companies including Goldman Sachs Group Inc. and JPMorgan Chase & Co. could extend at least until next year.

Federal rules permit Gensler, a Democrat, to remain as chairman of the U.S. Commodity Futures Trading Commission until the end of 2013. If President Barack Obama loses re-election in November, his successor could nominate a replacement as chairman earlier. White House spokeswoman Amy Brundage declined to comment on whether the president will re-nominate Gensler.

“It's a fight not worth having because he's in place for another year,” said Mark Calabria, an economist and the director of financial studies at the Cato Institute and a former senior aide for Republicans on the Senate Banking Committee. Calabria said he would be surprised if the administration formally submits Gensler for re-nomination this year.