The Chicago Cubs are leaving the station that's been their radio home for 90 years. WGN Radio president Jimmy de Castro confirmed on the air Wednesday media reports that the Cubs are leaving the station after this season. The Cubs say they'll hold a news conference on Thursday at Wrigley Field to announce a long-term broadcast deal with CBS-owned WBBM-AM 780. De Castro says the parting ways was a difficult decision for the station, which has been synonymous with the Cubs for close to century. But he says the decision was made after the station determined that the business deal the Cubs insisted on did not make economic sense for the station.