WASHINGTON (January 10, 2013)—U.S. Labor Secretary Hilda Solis has told colleagues she is leaving the Obama administration.

In an e-mail message, Solis said she submitted her resignation letter to President Barack Obama Wednesday afternoon.

She said she made the decision to leave after discussing it with her family and close friends.

Solis won praise from labor unions for aggressive enforcement of wage and hour laws and job safety regulations, but business groups have criticized her as not taking a more cooperative approach.