The Indy Racing League and the Champ Car World Series signed a deal today to unify the two American open-wheel series.

The agreement ends a 12-year conflict, bringing the two series under the umbrella of the IRL. The deal is expected to bring at least six current Champ Car teams into the IRL's IndyCar Series in time for the season-opening race at Homestead on March 29.

Champ Car co-owners Kevin Kalkhoven and Gerald Forsythe signed the agreement with IRL founder Tony George, IRL spokesman John Griffin said. Kalkhoven signed Thursday night, and George then flew to Chicago to get Forsythe's signature.

Griffin said details will be forthcoming in a news conference next week.