Pro-union organizing bill coming in U.S. House

WASHINGTON, March 9 (Reuters) - A bill making it easier for U.S. workers to unionize will be introduced on Tuesday in the House of Representatives, escalating a battle between congressional Democrats and corporate America.

The bill would let employees form a union if a majority of them in a workplace sign authorization cards.

That would change the present practice in which workers usually vote in elections on unionizing, although the bill would leave elections as an option for employees to choose.

The measure will be filed in the House by California Democratic Rep. George Miller, chairman of the House labor committee, said spokeswoman Rachel Racusen.

Known as the Employee Free Choice Act (EFCA), the bill was approved by the House in 2007 before it died in the Senate.

Supporters of the measure include President Barack Obama and Massachusetts Democratic Senator Edward Kennedy, chairman of the labor committee in the Senate.

Obama's support and increased Democratic majorities in Congress improve the bill's chance of full passage this year.

EFCA would also set timelines for first contracts between unions and employees, and raise fines on employers that violate employees' rights.

For labor unions -- which have long complained that elections allow anti-union managers to intimidate and harass workers -- no bill is more important than EFCA. Organized labor strongly backed Obama in last year's race for the White House.

For U.S. businesses, which generally seek to minimize union representation, no bill is as widely opposed. Both sides are pouring money into campaigns for and against the bill.

Retail analysts have said Wal-Mart Stores Inc (WMT.N), Home Depot Inc (HD.N), Lowe's Cos Inc (LOW.N), Target Corp (TGT.N) and Macy's Inc (M.N) face more unionization risk under EFCA. (Reporting by Kevin Drawbaugh; Editing by Tim Dobbyn)