Argentina striker Carlos Tevez signed for Manchester City on Tuesday and used his first news conference at the big-spending Premier League club to criticise Manchester United manager Alex Ferguson.
The 25-year-old, who spent two years at Old Trafford under a lease agreement, said Ferguson had not done enough to persuade him to stay at the champions.
City paid a reported 25.5 million pounds for Tevez whose "economic rights" were owned by agent Kia Joorabchian.
"Alex never called me or sent me any text messages," Tevez, who signed a five-year contract, said. "The only time he spoke to me was after the match against Roma because we had to discuss me playing for Argentina.
"I don't think that is the way to treat a player who has been two years at the club."
Ferguson said on Monday that he had personally tried to contact Tevez in January about extending his stay at United but that the striker had ignored his calls.
Tevez was the third major pre-season signing for City who are owned by Abu Dhabi billionaire Sheikh Mansour after midfielder Gareth Barry and striker Roque Santa Cruz.
City manager Mark Hughes confirmed that the club had also opened talks with Arsenal about buying Togo striker Emmanuel Adebayor.
"There's been contact and there is a deal to be done possibly but it's not been concluded as we speak here," Hughes said.
Tevez was a firm favourite at Old Trafford, scoring 34 goals in 98 appearances but often had to make do with a place on the bench. He was among the substitutes for the Champions League final defeat by Barcelona in May.
He said City's potential was a major factor in him moving across the city.
"Both the technical department and the ownership came with a very good proposal for me and this showed that they have the ambition to become one of the biggest clubs in the world," he said.
"Money was not a factor for me."
With Paraguay international Santa Cruz and possibly Adebayor in the squad next season, Tevez may have to fight for his place.
"In every team you have to win the respect of your team mates and sweat the shirt," he said. "I would not be happy if I was assured a first-team place."
City have been linked with Chelsea captain John Terry but Hughes would not be drawn on the speculation surrounding the England defender.
"I have fantastic respect for John Terry, as a great player and as an outstanding captain. But he is a Chelsea player at this moment in time so we have to respect that," he said.