Berbatov has seen his number of appearances per season decrease dramatically since joining United from Tottenham in 2008, with the 31-year-old featuring in just 21 games in all competitions last campaign. Berbatov, though, claims he is more disappointed that Sir Alex Ferguson did not make good on promises to give him more opportunities.
"We talked 10 times, he told me there would be a place for me but I stayed on the bench," Berbatov is quoted as saying in The Sun.
"My time at Manchester United is running out. I no longer feel like a valuable part of this team. I think I did well in the few opportunities that I received.
"I am a little frustrated by the way this happened, I do not think I deserved it. But I have dignity and I stopped going to such meetings, it is clear that I'm leaving United. It's obvious that I have to leave.
"I'm looking for a new place now. I know I can still play at the highest level."
United's rivals Liverpool are reported to be interested in Berbatov, but Serie A outfit Lazio may be favourites to snare the Bulgarian after his agent stated his desire to leave England earlier this month.