"Gazprom is studying the issue of buying a 20% stake in Repsol put up for sale by the Spanish construction company Sacir Vallehermoso," Zhukov said after a meeting of the Russian-Spanish inter-governmental commission for economic and industrial cooperation.
At the same time, Zhukov said the prospective deal was a private matter of the two companies.
Repsol is among the world's top 10 private oil and gas companies, selling about 55 million metric tons (403 million barrels) of oil and 32 billion cubic meters of gas annually.
Zhukov also said that Spanish energy companies were interested in developing gas deposits in Russia and implementing liquefied natural gas production projects.
Zhukov said the list of Spanish companies interested in energy cooperation with Russia included Repsol and the electric utility Iberdrola.
The materials prepared for Zhukov's visit to Spain say that Repsol is continuing negotiations on a possible joint venture with Russian company Tambeineftegaz to develop the Tambeisky field on the Yamal Peninsula in Russia's Arctic, and with U.S. Anadarco to implement a project for liquefied natural gas production and transportation.
Zhukov said Russia and Spain also had good prospects for cooperation in alternative energy projects, adding that Iberdrola had already signed a contract to build a wind turbine farm in southern Russia's Krasnodar Territory.
Zhukov also said Spanish company Tecnicas Reunidas had started the modernization of the Khabarovsk refinery in Russia's Far East under an $800-million contract.