LONDON (Reuters) - Half a century after their first live gig on London's Oxford Street, Mick Jagger, Keith Richards and the rest of the Rolling Stones will mark the band's 50th anniversary at a photographic exhibition on Thursday.

Guitarist Richards said this week that the Stones have met up for "a couple of rehearsals", fanning the fire of rumors that a new world tour may be in the works.

Richards would not go so far as to say when the quartet comprising himself, Jagger, Charlie Watts and Ronnie Wood would be performing in public again.

"There's things in the works - I think it's definitely happening," he told British broadcaster the BBC. "But when? I can't say yet."

"We're playing around with the idea and had a couple of rehearsals - we've got together and it feels so good."

The exhibition photos and an accompanying book track the rise of a group of fresh-faced British boys who played their first gig at Oxford Street's Marquee Club in 1962, became the scourge of the establishment in the 1960s, the titans of 70s music and finally the elder statesmen of rock n' roll in the 21st century.

"There was no sort of master plan," Richards says on the band's official website rollingstones.com. "We were flying by the seat of our pants. That is what amazes me, that the whole thing was improvised."

The relationship at the heart of the Stones' success remains the working friendship of singer Jagger and Richards, whose long musical partnership goes back to the days when they roomed with the late guitarist and former Stones founding member Brian Jones, hustling gigs wherevever they could find them.

"You have to put yourself back into that time," Jagger says on rollingstones.com. "Popular music wasn't talked about on any kind of intellectual level. There was no such term as ‘popular culture.' None of those things existed."

But the Jagger/Richards partnership has also had its chillier moments.

Earlier this year, Richards apologized to Jagger for derogatory comments he made about the lead singer in his 2010 memoir "Life", which caused a rift within the band.

In comments reported by Rolling Stone magazine, the two agreed it was time to settle their differences, leaving fans keen for another world tour breathing a sigh of relief.

"I got very involved with the business side of the Stones, mainly because I felt no one else was interested, but it's plain now from the book that Keith felt excluded, which is a pity," Jagger was quoted as saying. "Time I reckon to move on."

Richards added: "Mick's right. He and I have had conversations over the last year of a kind we have not had for an extremely long time and that has been incredibly important to me."

Some industry sources had put a tour delay down to the argument, but Rolling Stone said it may be more closely linked to concerns over Richards' health.

"The quality of the guitarist's performances declined after he suffered a head injury on vacation in Fiji in April 2006, midway through the Bigger Bang tour," the magazine said.

A Bigger Bang, the Stones' last tour, played to 4.5 million people in 32 countries over two years before it finished in London in 2007.

"The Rolling Stones: 50" picture book also hit the shelves on Thursday to correspond with the golden anniversary.

The new book features 700 illustrations, 300 of them in color and many taken from the archive of the Daily Mirror tabloid, which contains the largest newspaper collection of Rolling Stones photography.

"This is our story of 50 fantastic years," Jagger, Richards, guitarist/bass player Wood and drummer Watts said in a joint statement.

"We started out as a blues band playing the clubs and more recently we've filled the largest stadiums in the world with the kind of show that none of us could have imagined all those years ago."

The photographic autobiography, which also features words from the band, includes images taken by Philip Townsend, the photographer for the band's first ever shoot.

The 352-page hardback edition published by Thames & Hudson in Britain, will retail at 29.95 pounds ($48).

The Stones have said they also plan to release a documentary film in November chronicling their history.

The last studio album by the group was in 2005. They have released two live albums, 'Hampton Coliseum (Live 1981)' and 'L.A. Friday (Live 1975),' so far this year.

Richards said on rollingstones.com that he is grateful for the hallowed place that he and the band have carved into the hearts of their fans and in rock history, but was still striving to improve, half a century into his career.

"If you say I'm great, thank you very much, but I know what I am. I could be better, man, you know?"