The IBF has given Anthony Joshua a January 31 deadline to agree terms with mandatory challenger Kubrat Pulev otherwise he will be stripped of the title.
Joshua reclaimed his titles in Saudi Arabia last month when he avenged his shock loss to Andy Ruiz Jnr.
Joshua has underlined his desire to fight Deontay Wilder and Tyson Fury, but a showdown with the Bulgarian Pulev appears to be next on the cards.
An IBF spokesperson told Sky Sports: ‘I have just been told that the Pulev and Joshua camps have asked until January 31 to negotiate.’
If he fails to agree conditions for a fight he could lose the belt.
Joshua will also have to make room to face Oleksandr Usyk before long, as he is the mandatory challenger to his WBO title.