Junior middleweight titleholder Cory Spinks' overdue mandatory defense against former "Contender" star Cornelius "K9" Bundrage, scheduled for June 12, was postponed Wednesday, promoter Don King announced.

Spinks and Bundrage were due to meet at the Chaifetz Arena in Spinks' hometown of St. Louis.

King said "a number of conflicting interests factored into the decision to move the bout to a future card."

The most notable, according to King, was that St. Louis radio station, Hot 104.1 FM, which has helped him promote past fight cards, recently announced its "Super Jam 3" concert for the same day as the fight.

King said he preferred to not compete with a radio station that already has a commitment to be somewhere else on June 12, especially when both events draw from the same urban community and the boxing event was reliant on ticket sales because there was no television outlet.

Also, King is planning a higher-profile card in St. Louis on Aug. 7 on which junior welterweight titlist Devon Alexander, of St. Louis, will defend his title against former titleholder Andreas Kotelnik on HBO.

King's belief was that the two cards so close together would hinder ticket sales for Spinks-Bundrage in tough economic times.

It is likely that King will add Spinks-Bundrage to the Aug. 7 card, giving it three world title bouts. Light heavyweight titlist Tavoris Cloud is slated to defend his belt against former champ Glen Johnson in HBO's co-feature. Spinks-Bundrage would not be televised domestically.

"Cory told me he has been receiving messages from his fans saying they were disappointed that they could not attend both events," King said. "On top of that, I have now confirmed that I will be coming back to St. Louis with a world championship card in August, so it's really not best to have two boxing events competing with each other in the same market."

Refunds for tickets purchased for the June 12 card can be received from the original point of purchase, King said.

Spinks (37-5, 11 KOs) has not fought since reclaiming a vacant 154-pound belt by outpointing St. Louis rival Deandre Latimore on a split decision in April 2009.

This is the second time the fight with Detroit's Bundrage (29-4, 17 KOs) has been postponed. It was originally scheduled for March 26 in Las Vegas on an ESPN2 "Friday Night Fights" card, but called off when the main event, a cruiserweight title bout between Steve Cunningham and Matt Godfrey, was scrapped.