No one knows if it's the rain, volcanic ash hanging over Europe, the lack of blockbusters or the financial crisis but everyone seems to agree there has been a shortage of stars at this year's Cannes film festival.

Russell Crowe and Cate Blanchett led the festival opener "Robin Hood" but there is no Angelina Jolie or George Clooney to keep the buzz going, leaving paparazzi and video interviewers to chase the likes of Hollywood bad girl Lindsay Lohan.

"There's more star power in the jury than in any of the films," complained one industry publicist.

Kate Beckinsale, Benicio del Toro and director Tim Burton are all on the panel that will decide the competition winner, adding some glamour to the trademark Cannes mix of celebrity glitter and highbrow film artistry.

There have been sightings of big movie names like Johnny Depp and Michael Douglas but they have kept a lower profile than in other years and studios have cut back on the lavish parties used to generate excitement about films launched at Cannes.

Everything is relative and fewer Hollywood A-listers doesn't mean that the glamorous partying has entirely dried up along the palm-lined Croisette that fronts the Cannes bay.

Assorted celebrities from supermodel Naomi Campbell and party girl Paris Hilton to Rolling Stones frontman Mick Jagger have all put in appearances either to push new projects or luxury products or simply to enjoy the atmosphere.

"Cannes is always a bit of a laugh, you don't quite know what you are going to get, but I always enjoy the week," said Jagger, who has been spending time on software billionaire Paul Allen's yacht while promoting a new documentary on the band.

"I'll be dancing away, drinking champagne or whatever they throw at me I should imagine," he told Reuters Television.

BUSINESS OF CELEBRITY

Although the cinephiles and purists may disapprove, behind the glitter and the DJs, the stars play an important economic role at the world's biggest film festival.

At the Terrazza Martini, one of a row of sponsored party marquees set up along the beach, waiters are preparing cocktails in time for the arrival of Oscar-winner Jennifer Hudson, in Cannes to promote her planned film on Winnie Mandela.

Without her there to add glamour and name recognition, it could be hard to rouse media interest in the project and she does her part, chatting amiably and posing for pictures, one of which ends up on the cover of People magazine.

Similar operations have been underway across Cannes all week, sometimes to promote new films and sometimes to advertise luxury products like jewelry or fashion labels, and many celebrities charge large sums to lend their cachet to an event.

Singer Cheryl Cole, a big name in Britain who is trying to further a fledgling solo career, gave a short performance at a party for luxury jeweler Grisogono at the exclusive Hotel du Cap-Eden-Roc a short drive from Cannes.

"I just feel I have to be part of it, I suppose," she said. "It's very glamorous and beautiful and you just want to be a part of it."

But this year, the threat to flights posed by the ash clouds spewed from an Icelandic volcano, unusually cold and wet weather and the menacing state of the world economy have all contributed to a less lavish outlay than in previous years.

One beach party ran out of champagne half way through and not because there were too many people trying to drink it. Some parties have had to be canceled or pushed back because the promised stars bailed out at the last minute.

There has been a downbeat mood among event organizers and publicists although some have tried to look on the bright side.

"There's been far fewer people trying to crash the parties this year. That's one good thing," said one.