WASHINGTON (Reuters) - The U.S. House of Representatives approved a sweeping healthcare overhaul on Saturday, backing the biggest health policy changes in four decades and handing President Barack Obama a crucial victory.

On a narrow 220-215 vote, the House endorsed a bill that would expand coverage to millions of the uninsured and bar insurance practices such as refusing to cover people with pre-existing conditions.

The battle over Obama's top domestic priority now moves to the U.S. Senate, which is working on its own version. It has stalled there for weeks as Senate Democratic leader Harry Reid searches for an approach that can win the 60 votes he needs.

(Editing by Todd Eastham)