U.S. service workers union to endorse Obama

WASHINGTON (Reuters) - Sen. Barack Obama's presidential campaign could get a boost when it wins an expected endorsement from a key labor group on Friday.

The 1.9 million-member Service Employees International Union was expected to announce the endorsement later in the day, a union official said.

The SEIU, one of the fastest-growing labor organizations in North America, represents health care and other service industry workers.

The endorsement should help Obama in his battle for the Democratic presidential nomination against Sen. Hillary Clinton going into the March 4 primaries in Texas and Ohio.

The two contests are crucial for Clinton, a New York senator who would become the first woman U.S. president.

Obama, who also would make history as the first black U.S. president, hopes the momentum from a string of February primary victories will help him carry Texas and Ohio.

The endorsement will allow Obama, an Illinois senator, to tap into the Washington, D.C.-based union's staff resources and fund-raising abilities to help his campaign.

(Reporting by Donna Smith; Editing by Eric Walsh)