Shania Twain, Britney Spears and Whitney Houston are the favourites to scoop honours at the American Music Awards in Los Angeles on Monday.

The trio have three nominations each in the awards, which are voted for by a poll of US music buyers.

Performers appearing on the show - televised across the US - include Beck, Mariah Carey, Jennifer Lopez and Eurythmics. Spice Girls singer Mel C will be among the celebrities presenting prizes at the event, taking place at the Shrine Auditorium.

But little will be seen of the three favourites for awards - Britney Spears is scheduled to perform a medley of her hits, but Shania Twain and Whitney Houston will be staying away.

It is an unwritten rule that acts who appear on the AMA show cannot appear on the Grammys, which take place a month later.

Grammys producer Ken Ehrlich defends this rule, saying: "We think it's our responsibility to our audience to give them a fresh look at performers.

"I don't want to say it's a policy. It's an understanding in the music industry that we all make the effort to keep these shows different."

AMA organisers disagree. Spokesman Paul Shefrin says: "If you're preventing an artist from making an appearance, you're hurting that artist's sales."

But the American Music Awards sets itself up as a people's awards show, a world apart from the venerable Grammys.

They are voted for by a poll of 20,000 US music buyers, with the 20 categories decided by sales figures and radio airplay.

The Grammys, due to be held on 23 February, are decided by an academy.

Female domination

While Spears, Twain and Houston lead the AMA nominations with three each, the top men are pop idols the Backstreet Boys, heart-throb Ricky Martin, country stars Garth Brooks and George Strait, rapper Kid Rock and Carlos Santana, with two nominations each.

Also with two nominations each are Lauryn Hill, Jennifer Lopez, TLC and country trio The Dixie Chicks.

The only UK representative is Phil Collins, who faces Cher and Shania Twain in the favourite adult contemporary artist category.

British music fans awaiting their own awards have to wait this year - the nominations for the 2000 Brit Awards will be announced on 31 January, with the ceremony taking place on 3 March.