Marmol, who had to waive his no-trade close to accept the deal, was due to make $9.1 million in 2013 in the last year of his three-year, $21 million contract.
Marmol appeared in 61 games for the Cubs in 2012, earning 20 saves and going 3-3 with a 3.42 ERA.
In his seven-year career, all spent in Chicago, Marmol appeared in 452 games, compiling 115 saves, a record of 21-28 and a 3.38 ERA. He was a National League All-Star in 2008. He pitched for the Cubs in the postseason in 2007 and 2008.