Prokhorov will receive an 11% stake in RusAl, the aluminum giant, and a cash payment.
RusAl said in a press release that the merger would "provide the scale and scope to allow the enlarged company to compete more effectively with the newly emerging global majors."
Prokhorov and Interros President Vladimir Potanin are two key shareholders of the Russian metals giant Norilsk Nickel. Both businessmen announced early this year plans to divide assets.
Prokhorov held 28.2% and Potanin 25.3% of Norilsk Nickel's shares as of October 26.