OLEKSANDR USYK has been ordered to start negotiations to defend his WBO heavyweight title against Joseph Parker – potentially scuppering Daniel Dubois’s hopes of a rematch with the Ukrainian.

The WBO announced today that Usyk, who also holds the WBC and WBA crowns, has 30 days to “reach terms” for a mandatory title defence against New Zealand’s Parker or the sanctioning body will call for purse bids.

Parker defended his WBO interim title in Riyadh, Saudi Arabia, last month with a second-round stoppage victory over Martin Bakole, a late replacement after Dubois withdrew because of illness.