Washington — In an effort to avert a presidential veto, Senate leaders have stripped language from a pending appropriations bill that would have expanded federal financing for research on human embryonic stem cells.

The deleted provision would have allowed federal money to be spent on research involving stem-cell lines derived before June 15, 2007, nearly six years after an August 2001 deadline set by President Bush. Scientists supported that expansion, but it was opposed by social conservatives and Mr. Bush, who had threatened to veto the bill over the provision.

The move to drop the controversial language came this afternoon, at the start of floor debate on the spending bill, which covers, among other agencies, the Departments of Education and Health and Human Services for the 2008 fiscal year, which began two weeks ago. The Senate is expected to debate the bill for the rest of the week.

“We wanted to show that we are willing to compromise,” said Sen. Tom Harkin, a Democrat of Iowa, in a floor statement. “We’re willing to try to meet the president halfway.”

But it’s unclear whether the concession will satisfy Mr. Bush, who has also threatened to veto the bill over its spending level. The Senate bill would appropriate $11-billion more for health, education, and labor programs than the president had proposed. The House passed its version of the bill in July. —Kelly Field