OAKLAND — Naming rights for the Coliseum have opened up again with Overstock.com having informed the Coliseum and the A's the company is opting out of the naming rights with the Coliseum.

The company will continue to have a corporate sponsorship agreement with the A's that includes some in-stadium signage.

So what had formally been called the O.co Coliseum for the last five years will revert to being just the Coliseum. Overstock.com signed a six-year deal worth $7.2 million in 2011, with half the money going to the Oakland Raiders and half split between the City of Oakland and Alameda County.

The last time the Coliseum was without corporate sponsorship was the period 2008-11 after McAfee Inc. declined to extend its deal for naming rights.