WASHINGTON, May 7 (Reuters) - A bill to help Haiti rebuild after its devastating earthquake by opening the U.S. market to more clothes made in the Caribbean nation was headed on Friday 7 May to President Barack Obama for his signature.

The U.S. Senate approved the bipartisan Haiti Economic Lift Program (HELP) Act on voice vote late on Thursday 6 May, one day after the House of Representatives approved the measure.

"Improving access to the U.S. market for Haitian textile and apparel products is a widely-supported, common-sense approach to provide long-term support for a lasting recovery in Haiti," Senate Finance Committee Chairman Max Baucus, a Democrat, said in a statement.

The clothing sector accounted for 75 percent of Haiti's export earnings and employed more than 25,000 people before the Jan. 12 earthquake that killed more than 300,000.

"This bill reflects a carefully crafted bipartisan, bicameral compromise that balances the concerns of domestic producers with providing meaningful trade benefits for Haiti's apparel sector," said Senator Charles Grassley, the top Republican on the Finance panel.

The HELP Act makes it more attractive for clothing manufacturers to invest in new facilities in Haiti by extending the country's duty-free access to the U.S. clothing market under two separate programs through September 2020.

It increases two separate duty-free quotas for certain Haitian knit and woven clothing products to 200 million square meter equivalents (SMEs), from 70 million currently, but contains certain limits within that to protect U.S. producers.

A leading development group and a retailers association praised the legislation.

"Haitians aren't looking for a hand-out, they want a leg up," said Stephanie Burgos, senior policy adviser at Oxfam America. "With income from jobs in the apparel industry and elsewhere, they can feed and care for their families, send their children to school, and build lasting shelter."

Stephanie Lester, vice president for trade at the Retail Industry Leaders Association, said the bill would help create "thousands of new jobs that are desperately needed" in Haiti. (Reporting by Doug Palmer; Editing by Vicki Allen)