GRAMMY-winning singer Michelle Branch has embarked on a bitter battle with pop superstar MADONNA - because she no longer wants to be on the MATERIAL GIRL's record label.

The 19-year-old brunette wants to disassociate herself from her former mentor Madonna and filed a petition with the CALIFORNIA LABOUR COMMISSION this week (ends21MAR03) claiming she should be let out of her contract with MAVERICK RECORDS because they signed her up for sponsorship she didn't want.

Maverick's lawyer BERT FIELDS says, "She claims one of (Maverick parent) Warner Brothers' entities got 'tour support' without her permission.

"She says they acted as unlicensed talent agents. We think there's no merit to the case, and both sides hope this can be resolved."

A source at Maverick tells American website PAGE SIX, "This is all about money. She wants more. Record companies face this stuff all the time and every now and then an artist pulls a (James) GANDOLFINI."

But Madonna is desperate to keep Branch, says another source, who explains, "Madonna needs to keep Michelle. Maverick hasn't had a big act like her since Alanis Morissette and all the other labels are all lining up to sign her if she leaves."