The first Lewis-Tyson fight was a one-sided affair

Tyson said after his 49-second win against Clifford Etienne in Memphis last month that he needed more time before facing Lewis again.

But Lewis and his camp say they will have to find another opponent to fill the June date if the former champion fails to commit to a rematch.

"We must make a formal announcement next week," said Lewis' business manager Adrian Ogun.

"We are working to a very, very tight schedule with regard to a rematch with Mike Tyson so we have to have a formal response back from [cable TV network] Showtime and Tyson by the end of next week."

There is an opportunity to a deal with Vitali Klitschko Adrian Ogun Lennox Lewis' manager

Lewis dominated Tyson over eight rounds last summer in Memphis, but a rematch is one of the British fighter's most lucrative options because of a shortage of viable opponents.

A possible opponent for Lewis if Tyson fails to agree terms is Vitali Klitschko, the Ukrainian fighter whose brother Wladimir was recently knocked out in two rounds by Corrie Sanders

"We have been talking with other interested parties and there is an opportunity to revisit Vitali Klitschko and find out whether they (Klitschko's promoters) would like to do a deal based on a voluntary defence," said Ogun.

"At the moment Lennox is exploring all his options and they include fighting and not fighting and all the possible consequences. The conditions have got to be right for him."

Lewis ruled out the chance of fighting Sanders, who was in London on Wednesday.

Klitschko stunned by Sanders

WBO champion Sanders will instead look towards either a rematch with Wladimir Klitschko or a meeting with IBF champion Chris Byrd.

"I don't care who they get for me as long as it's worth it," said the South African.