The Chicago Cubs and pitcher Edwin Jackson agreed to terms on a four-year, $52 million deal, a source told ESPN's Jim Bowden on Thursday.

Jackson, 29, was 10-11 with a 4.03 ERA in 31 starts (189 2/3 innings) with the Washington Nationals in 2012. The Nationals did not make a qualifying offer to Jackson, so they won't get any draft-pick compensation should he leave.

Jackson's deal includes an $8 million signing bonus with annual salaries of $11 million per year, according to a Cubs source.

The Cubs added another right-handed pitcher in Carlos Villanueva, who has agreed to a two-year contract, a major league source told ESPNChicago.com's Bruce Levine. The deal is pending a physical.

Villanueva, 29, was 7-7 with a 4.16 ERA in 38 appearances with the Toronto Blue Jays in 2012, including 16 starts.