McCartney and Mills were married for four years, split up in 2006 and have a 4-year-old daughter together.

The former couple was not able to reach a divorce settlement earlier this month and so a decision regarding the division of their substantial assets will be made by a judge. The divorce hearings were held in private.

The Judicial Communications Office told the BBC the judge hearing the case is expected to hand down his ruling March 17, then decide "whether or not to make the judgment public in whole or in part."

The amount McCartney will be ordered to pay Mills could set divorce records in Britain, the BBC said.

McCartney, the former Beatle and British rock 'n' roll icon, is said to be worth about $1.6 billion.