Michael Jackson Estate Clears MJ's MASSIVE Debt ... Almost

Michael Jackson's estate has made a fortune since the singer's death -- so much in fact ... it's nearly paid off $500 million in debt the King of Pop left behind when he died.

Executors for the Estate filed legal docs -- obtained by TMZ -- which show the Estate has generated gross earnings exceeding $475 million as of the end of May.

According to the docs, all of MJ's debts have been paid, with the exception of a BIG debt involving Michael's publishing catalog ... and executors expect that will be fully paid off by the end of the year.

It's not only good news for the Estate ... it's great news for the small army of lawyers who have been handling all the legal and business affairs. Their fees -- from May, 2010 through November, 2011 -- exceeded $13.6 MILLION!

Two other things ... Katherine is asking for an additional $34,700 a month to pay for lawyers and accountants, and another $205,041 to cover lawyer and accountant fees from 2011.

Final thing --There are still some unresolved creditors' claims and several lawsuits to clear up.