Award-winning composer Marvin Hamlisch’s Upper East Side co-op has struck a sour note with T-Mobile.

The cellphone company filed suit yesterday in Manhattan federal court against the 970 Park Ave. Owners Corp. for trying to jack up the rent on antennas affixed to the swanky high-rise.

The suit seeks a court order enforcing terms of a 1997 contract under which T-Mobile pays nearly $4,900 a month. The co-op allegedly tried to raise the rent by $1,250.