When Ruslan Chagaev and Nikolai Valuev met 11 months ago, Chagaev claimed a majority decision to win a heavyweight world title.
Now, they will meet again on May 31 in Germany, Chagaev's German-based promoter said Monday.
The announcement from Universum Box-Promotion came after the company won a WBA-ordered purse bid in Panama to gain control of the mandatory fight.
Universum bid $4,354,840 to easily beat a bid of $3,541,021 from Sauerland Event, Valuev's promoter, which is also based in Germany. Don King Productions bid $3 million.
Under the rules of the bid, Chagaev, as the titleholder, is entitled to 75 percent of the winning bid ($3,266,130) with Valuev entitled to 25 percent ($1,088,710).
Since the loss to Chagaev, the 7-foot, 320-pound Russian giant Valuev (48-1, 34 KOs) has won two fights. One victory was a lopsided decision against Jean Francois Bergeron in September while the second was a shutout decision against former titlist Sergei Liakhovich in an elimination bout that earned him the rematch.
Chagaev (24-0-1, 17 KOs), who was sidelined for several months with an illness, made his first title defense on Jan. 19, a unanimous decision against England's Matt Skelton.
Dan Rafael is ESPN.com's boxing writer.