The 33-year-old has a contract with the Bavarians until the summer of 2023 but wants to explore a new challenge elsewhere.
Lewandowski joined Bayern Munich from Borussia Dortmund on a free transfer in the summer of 2014 and has won eight Bundesliga titles in his time at the club.
The Poland international's list of honours at the Allianz Arena also include one UEFA Champions League, three DFB-Pokals, one UEFA Super Cup and one FIFA Club World Cup.
"I can confirm that I spoke to Hasan [Salihamidzic] and informed him that the decision was made... and that I am not extending my contract with FC Bayern," Lewandowski explained to Sky on Saturday.
"Both sides have to think about the future. It's best if we find the best solution for both sides"
"I said [Salihamidzic] that if an offer comes, then we have to think about it - also for the club. Both sides have to think about the future. That's all I can say."
Bayern sporting director Salihamidzic confirmed Lewandowski's stance, telling Sky: "I spoke to Lewa. In the conversation he told me that he did not want to accept our offer to extend the contract and that he would like to leave the club," Bayern director of football Hasan Salihamidzic told Sky Sport Germany ahead of Bayern's game with Wolfsburg.
"He said that he would like to do something else. But our attitude hasn't changed.
"Lewa has a contract until June 30, 2023. That's a fact. I don't deal with that because our stance has always been clear."
Lewandowski's was once again on target in Bayern's final game of the season on Saturday, scoring his 35th Bundesliga goal in a 2-2 draw with Wolfsburg.
