DUBAI, June 21 (Reuters) - Saudi Arabia's government and a Russian state fund have signed a memorandum of understanding to jointly invest as much as $10 billion, official Saudi news agency SPA said on Sunday.

The deal between Saudi Arabia's Public Investment Fund (PIF) and the Russian Direct Investment Fund (RDIF) was sealed last week when top Saudi officials visited Russia. The governments also agreed to cooperate on developing nuclear energy. ID:nL5N0Z5163

SPA did not say where or when the joint investments would be made. The PIF was set up to help develop the Saudi economy, while the RDIF makes equity investments mainly in Russia and in the last few years has signed similar co-investment agreements with countries such as China, South Korea and Kuwait.

Prince Saud K. Al Faisal, executive director for investment policy at the Saudi Arabian General Investment Authority, told Reuters in March that Saudi Arabia was increasingly focusing on investing to obtain technology and benefit its economy rather than just seeking monetary returns. ID:nL6N0WW31Z

Last week the PIF agreed to buy a 38 percent stake in South Korean builder POSCO Engineering & Construction Co for about $1.1 billion, in a deal that could transfer construction sector expertise to Saudi Arabia.

(Reporting by Andrew Torchia; Editing by Hugh Lawson) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))

Keywords: SAUDI RUSSIA/FUNDS