Michelle Obama, Wife of Presidential Hopeful Barack Obama, Quits Board of Wal-Mart Supplier

The wife of Democratic presidential candidate Barack Obama resigned Tuesday from the board of a food supplier for retail giant Wal-Mart Stores Inc., a target of criticism by the Illinois senator.

Michelle Obama cited the increased demands of his campaign for leaving the board of Westchester, Ill.-based TreeHouse Foods Inc. Her position had raised questions because Obama has praised a union-led effort to change working conditions at Wal-Mart.

TreeHouse Foods said in a Securities and Exchange Commission filing that her resignation from the position she has held since 2005 was not due to any disagreement with the company. Last year she earned $51,200 in fees from the company, according to the couple's 2006 tax returns.

"As my campaign commitments continue to ramp up, it is becoming more difficult for me to provide the type of focus I would like on my professional responsibilities," Michelle Obama said in a written statement.

An administrator at the University of Chicago Hospitals, she has significantly curtailed her work hours to campaign for her husband.

The company supplies retail grocery chains with pickles, nondairy powdered creamer and other products. Wal-Mart was its largest customer last year, according to an SEC filing.

Obama and other Democratic presidential contenders have been critical of Wal-Mart, which has taken heat over the wages and benefits it pays employees. The Arkansas-based company has defended its wages.

One of Barack Obama's chief Democratic rivals, Sen. Hillary Rodham Clinton of New York, once served on Wal-Mart's board but since has become a critic of its business practices.

Last year, before he declared his candidacy for president, the Illinois senator courted the union-backed group WakeUpWalMart.com.