The use of methyl formate instead of methanol-carbon monoxide, in oxidative carbonylation of alkenes catalyzed by the system Pd-II/Cu and giving in one step olefinic ester, has been investigated. In this reaction methyl formate acts as a source of alkoxy, but an initial partial pressure of CO (up to 4-5 bar) is required in order to obtain the carbonylation products in high yield. However, CO handling can be avoided by an in situ partial decarbonylation of methyl formate catalyzed by lithium methoxide prior to the oxidative carbonylation.