It means that the prospect of Lewis facing a rematch with Mike Tyson is now much more likely.

Lewis had faced a deadline of Thursday to agree to a match-up with Byrd but issued a statement detailing why he felt the American offered him no challenge.

"If I were to fight Chris Byrd, my likely next IBF mandatory defence would be against an opponent [David Tua, Evander Holyfield or Hasim Rahman] that I have already beaten," added Lewis.

"The fact is that the champion makes the belt important, not the other way round.

"Accordingly, in light of a court order and an IBF ruling that would have required me to fight a meaningless fight against Chris Byrd in order to keep the IBF belt, I had no choice but to vacate.

"As I have recently stated, the world has yet to see the best of Lennox Lewis."

The decision leaves Lewis, who once held all versions of the heavyweight crown - with just the World Boxing Council belt.

And it would appear to prove that the 37-year-old plans to carry on fighting, something he had hinted at last week.

Lewis is believed to be in negotiations about a new three-fight deal involving a rematch against Mike Tyson and defences against the Ukrainian Klitschko brothers.

The first fight would reportedly be against 26-year-old Vitali Klitschko in the United States in December.