*Failure to pass bill would be major blow to Obama

*Democratic leader sees close vote on Saturday

*House leaders still working to resolve some issues (adds standing of bills, details)

WASHINGTON, Nov 5 (Reuters) - U.S. House of Representatives Democratic leader Steny Hoyer on Thursday said he expected the House to pass a sweeping healthcare overhaul on Saturday, but acknowledged that the vote would be close.

Failure to pass the bill in the Democratic-led House would be a major political blow to President Barack Obama who has made reforming the country's hugely expensive healthcare system a top domestic priority and wants a bill passed this year.

"I think it's going to be close," Hoyer told a small group of reporters about Saturday's vote but said that it would win majority support from Democrats.

House leaders are working through some last minute details to settle concerns by some Democrats over abortion and immigration issues.

Republicans oppose the sweeping overhaul -- which is aimed at reining in costs, expanding coverage to millions of uninsured and barring insurance practices such as denying coverage to people with pre-existing conditions. They are expected to vote against the bill in the House.

The Senate's version of a healthcare bill has been bogged down as Democratic leaders await cost estimates from congressional budget analysts and search for an approach that could win the 60 votes needed to overcome Republican procedural hurdles.