The school had originally announced Tressel would miss only two games for NCAA rules violations.
Five Ohio State players were found to have sold memorabilia during the past year, a violation of NCAA rules. Those players were suspended for the first five games of next season and Tressel was given only a two-game suspension even though he knew of the violations and kept that knowledge secret.
Ohio State Athletic Director Gene Smith said Tressel asked that his suspension be increased to match that of the players. Tressel was also fined $250,000.
"I have accepted his request and we are taking action to notify the NCAA," Smith said in his statement. "Until the NCAA has completed its investigation, we will not be publicly discussing the details of this case."
"Throughout this entire situation my players and I have committed ourselves to facing our mistakes and growing from them; we can only successfully do that together," Tressel said in a statement released by the school. "I spoke with Athletics Director Smith and our student-athletes involved, and told them that my mistakes need to share the same game sanctions.
"Like my players, I am very sorry for the mistakes I made. I request of the university that my sanctions now include five games so that the players and I can handle this adversity together."
The players involved were allowed to compete in Ohio State's 31-26 win over Arkansas in the Sugar Bowl.