JERUSALEM, May 8 (Reuters) - The British cosmologist Stephen Hawking has pulled out of a prestigious Israeli conference as part of an academic boycott to protest against Israel's occupation of Palestinian lands, Cambridge University said on Wednesday.

After conflicting explanations were given for Hawking's decision, a spokesman for the British university confirmed that the wheelchair-bound scientist was snubbing the annual event, organized by President Shimon Peres, as part of the boycott.

We have now received confirmation from Professor Hawking's office that a letter was sent on Friday to the Israeli President's office regarding his decision not to attend the Presidential Conference, based on advice from Palestinian academics that he should respect the boycott, the spokesman said.

We had understood previously that his decision was based purely on health grounds having been advised by doctors not to fly.

Hawking, who has won international recognition for his work on black holes, had been flagged as a major speaker at the conference, alongside former U.S. president Bill Clinton and former British prime minister Tony Blair.

By snubbing the event, Hawking, author of the best-selling A Brief History of Time, has become one of the most prominent scientists to join the boycott movement.

His name was quietly withdrawn from the list of participants this week and the organizers on Wednesday criticized his withdrawal.

The academic boycott against Israel is in our view outrageous and improper, certainly for someone for whom the spirit of liberty lies at the basis of his human and academic mission, conference chairman Israel Maimon said in a statement.

The British-based Palestine Solidarity Campaign released what it said were extracts of Hawking's letter to the conference organizers in which he explained his decision.

I have received a number of emails from Palestinian academics. They are unanimous that I should respect the boycott, his letter said, according to the PSC.

In view of this, I must withdraw from the conference. Had I attended, I would have stated my opinion that the policy of the present Israeli government is likely to lead to disaster.

Numerous figures from the world of art and entertainment have refused to perform in Israel in recent years as part of an effort to promote the Palestinian cause, including British singer Elvis Costello and the U.S. indie rock band the Pixies.

Direct peace talks between Israel and the Palestinians broke down in 2010 over the issue of continued Jewish settlement building on land seized in the 1967 war. The Palestinians want to create an independent state on the captured territories.

The United States is seeking to revive the negotiations. (Additional reporting by Estelle Shirbon and Michael Holden in London; Writing by Crispian Balmer; Editing by Kevin Liffey)