This summer alt-rockers The Offspring and 311 will be joining forces as co-headliners for the 2010 Unity Tour. The trek will be featuring Pepper as a special guest as well.

The outing will kick off in Chicago on June 29. So far 18 cities are scheduled to be visited through the end of July.

311, before taking the Unity Tour on, will have some US festival appearances and headlining dates in April as well as June.

“Uplifter” the ninth album from 311 was released last summer, debuting in the No. 3 spot on Billboard’s 200 chart. It was the highest charting album for 311 ever. The set was recorded with Bob Rock (Motley Crue, Metallica), the highly regarded hard rock producer.

Currently The Offspring are working on an album to follow up “Rise and Fall, Rage and Grace” from 2008. The band is planning to take a studio break to participate this summer on the Unity Tour. According to a recent press release, fans will be able to hear new material in the forthcoming shows.

The most recent studio album from Pepper, “Pink Crustaceans and Good Vibrations,” was released in 2008.