This invention relates to a coextruded, transparent, biaxially oriented polyester film comprising a base layer (B) and a heatsealable top layer (A) which is peelable from at least the APET side of an APET/CPET tray, the heatsealable and peelable top layer (A) consisting of a) 50 95% by weight of polyester and b) 5 40% by weight of a polyester-incompatible polymer (=anti-PET polymer) based on the mass of the top layer (A), wherein c) the polyester is composed of 20 95 mol % of units derived from at least one aromatic dicarboxylic acid and 5 80 mol % of units derived from at least one aliphatic dicarboxylic acid, and d) the layer thickness d.sub.A is from 1.3 to 3.0 .mu.m.The invention further relates to a process for producing the film and to its use.