WASHINGTON (Reuters) - President Barack Obama will seek to shore up support for his economic agenda from Big Labor in White House talks on Friday, just days after he tried to mend fences with Big Business at a similar meeting.

Obama will meet leaders of about a dozen of the country's largest unions to discuss "strengthening our economy, spurring growth and creating good jobs for the American people," the White House said on Thursday.

The meeting comes as Obama faces fresh complaints from the labor movement, whose backing in the 2008 election helped sweep him into office, over parts of a compromise tax accord he reached with Republicans and a revised trade deal with South Korea this month.

Obama will convene the labor gathering three days after he sat down with some of the country's top CEOs in a bid to improve strained relations with the corporate world. At the meeting, he prodded them to spend more of big business's estimated $2 trillion cash hoard to boost U.S. hiring.

Among those expected on Friday will be AFL-CIO President Rich Trumka, United Steelworkers President Leo Gerard, United Auto Workers President Bob King and American Federation of Teachers President Randi Weingarten.

Obama is trying to keep working-class Americans on his side despite signs of flagging support amid high U.S. unemployment and tepid growth.

Organized labor stood behind Obama's economic stimulus program and overhauls of the healthcare system and financial regulations. But some union leaders have grown frustrated he has not done more to boost job creation.

Labor leaders have supported Obama's bid to keep expiring Bush-era tax cuts for the middle class but have been less enthusiastic about his acceptance of a Republican demand to include wealthier Americans in the two-year extension of lower rates. Some have also criticized Obama's acceptance of reductions in the federal estate tax.

(Reporting by Matt Spetalnick; Editing by Peter Cooney)