"After 12 years, I have seen it all and done it all," Mason told jocklife.com. "Right now, I am content with the decision I am making. All good things come to an end, and I am ready to see what else life has to offer."
But Mason has not informed the team of his decision.
"For any player to retire, he has to send a letter to the NFL stating this. Derrick Mason has not done that," said Kevin Byrne, the Ravens' senior vice president of public relations.
Mason's agent, Peter Schaffer, did not immediately respond to a phone call and e-mail from The Associated Press.
But Schaffer's partner, C. Lamont Smith, told jocklife.com, that Mason "advised me that after careful and deep thought he had made a decision to retire from professional football. ... Given that Derrick just reached this decision on Friday, he has not as of yet filed official papers with the league offices."
Smith said Mason would decline any interview requests over the next two weeks.
Mason, 35, played a key role in helping Baltimore reach the AFC championship game last season. He started all 16 games and led the Ravens in receptions (80) and yards receiving (1,037). He then added 12 catches for 190 yards and a touchdown in three playoff games.
Mason played eight seasons with the Tennessee Titans and four years with the Ravens. Last season he became the 31st player in NFL history to reach 10,000 career yards receiving.
He insisted the announcement had nothing to do with his drive during the offseason to get a better contract.
"I have made enough money, more than enough money," Mason said.
"We're losing a great player," Ravens running back Le'Ron McLain said. "I hope every receiver plays like him, practices like him and acts like him."