The club's top goal scorer of the season was thought to be considering a move after Sir Alex Ferguson declined to select him for his squad in the Champions League final against Barcelona on Saturday. Ferguson opted to place Michael Owen on the bench in his stead.
"I will stay," the striker is quoted as telling Bulgarian media. "I will fight for the 20th title. If I were an easy quitter, I would never have made it this far. Everything at Manchester United starts from scratch for me on July 4."
Speculation that his time at Old Trafford might be over was fuelled by his absence from the stands on Saturday, which he has now attributed to 'shame'.
"I want to apologise to everyone for not taking part in the final," he continued. "I hoped to make the whole of Bulgaria happy with my play. This did not happen and I can only say I am sorry for myself and for the Bulgarians who expected to see me.
"The truth is that I stayed at the dressing room and watched the Champions League final there, on a TV screen. I was really disappointed. I was ashamed that I was not part of the team and did not want people to see how sad I feel."
Berbatov was the joint recipient of the Golden Boot award this season with 21 goals.