The Bulgarian had been tipped to leave Old Trafford after boss
Alex Ferguson left him out of his Champions League final squad for
the defeat against Barcelona.
But he is determined to prove he has a future with the Red
Devils and has vowed to fire them to their 20th league
championship.
The Premier League's joint Golden Boot winner, 30, said: "I will
stay. 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."
Berbatov scored 21 goals as United won the Premier League with a
nine-point margin over second-placed Chelsea.
However, he found his first team chances limited towards the end
of the campaign following the emergence of Mexican sensation Javier
Hernandez.
And it was Hernandez who partnered Wayne Rooney up front in the
3-1 Champions League final loss to Barca last weekend.
But Berbatov reckons there will be plenty of opportunities for
him to prove his worth to United in the future.
He added: "I want to apologise to everyone for not taking part
in the final.
"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.
"But there will be new finals and we will be fighting for new
titles. I am moving ahead. When you go through difficult times, you
should not quit.
"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."