* Some Senate moderates seek tight ban on funding

* Senate Finance chairman says issue will be worked out

By Donna Smith

WASHINGTON, Nov 9 (Reuters) - A fight over abortion could complicate Senate action on a sweeping U.S. healthcare reform bill as some moderate Democrats on Monday voiced support for a strict ban on using federal funds to pay for the procedure.

Senator Ben Nelson, a moderate Democrat, said he supports abortion language similar to a bill passed by the House of Representatives and would oppose any Senate bill that did not clearly ban the use of federal money for abortions.

"If it doesn't make it clear that it does not pay for abortion then I wouldn't support it," Nelson, who has voiced a number of concerns about the proposed healthcare overhaul, told reporters.

Senate Democratic Leader Harry Reid is struggling to muster the 60 votes needed to advance healthcare reform in the 100-member chamber and he cannot afford to lose any Democrats over the abortion issue.

"It's an additional complication," said Senate Finance Committee Chairman Max Baucus, whose panel shaped the Senate bill. "We'll work it out. We have to get healthcare passed this year and we will."

The House included in its healthcare bill a measure that bars anyone receiving federal subsidies from buying a health policy that covers abortion. A proposed government-run insurance plan, known as the public option, also would be barred from covering abortion.