To obtain a hydroxy ester by reducing a keto ester.

In reducing a keto ester in the presence of a complex of formula (1) MXY (PR1R2R3)n (NHR4-A-NHR5)m (1) or formula (2) MXYL (NHR4-A- NHR5)m (M is a transition metal of the group VIII; X and Y are each a hydrogen atom, a chlorine atom, a bromine atom or an iodine atom; R1, R2 and R3 are each an aryl group or an alkyl group; R4 and R5 are each hydrogen, an alklsulfonyl group, an arylsulfonyl group, an alkylcarbonyl group or an arylcarbonyl group; A is an ethylene group substituted with an alkylene group or an aryl group; n and m are each 1 or 2; L is a phosphine compound of bidentate) as a catalyst, the reaction is carried out at ≥50°C.