Sarah Hall Wed Feb 27, 3:47 AM ET

Los Angeles (E! Online) - They couldn't work it out and now judgment day looms for Paul McCartney and Heather Mills.

After the former couple was once again unable to hammer out a divorce settlement over five days of closed-door hearings this month, High Court Justice Hugh Bennett has announced that he will deliver a decision in the split on Mar. 17.

The judge's ruling will determine what portion of his fortune—estimated at a whopping $1.64 billion—McCartney will be ordered to hand over to Mills. It is unclear whether the decision will be made public.

Legal experts believe that Mills is demanding somewhere in the neighborhood of $100 million, while McCartney is offering her significantly less money to finally put an end to their four-year marriage.

Should either party disagree with the judge's decision, the case would move to the Court of Appeal, where all hearings would be open to the public and all details of the proceedings revealed.

Mills parted ways with her divorce attorneys in November and represented herself in the legal battle, while McCartney was represented by high-powered legal eagle Nicholas Mostyn.

The ex-twosome tied the knot in June 2002 and welcomed daughter Beatrice in October 2003.

They announced their separation in May 2006 and McCartney filed for divorce two months later.