Connery played Indy's father in 1989's Indiana Jones and the Last Crusade, the third instalment of the franchise directed by Steven Spielberg and produced by George Lucas.

"I get asked the question so often, I thought it best to make an announcement,'' Connery, 76, said in a statement posted last Thursday on Lucasfilm's Indiana Jones website. "I thought long and hard about it, and if anything could have pulled me out of retirement it would have been an Indiana Jones film.''

"I love working with Steven and George, and it goes without saying that it is an honour to have Harrison as my son,'' he said. "But in the end, retirement is just too damned much fun.''

The fourth Indiana Jones film, not yet titled, is again directed by Spielberg and produced by Lucas. Shooting begins the week of Monday, June 18, at an undisclosed US location, and the movie is due out May 22, 2008.

Lucasfilm also announced Thursday that Cate Blanchett, John Hurt and Ray Winstone will be joining the cast, which along with Ford, includes Shia LaBeouf.