Playboy Mansion SOLD!

Hugh Hefner can officially slap a "SOLD" sign onto his Playboy Mansion, and then head back inside for dinner ... after hammering out a deal with the PBR heir who almost lost it 11 days ago.

The escrow closed Tuesday for Hef's neighbor Daren Metropoulos -- and we're told it went for a final price of $100 million ... a nice discount off the $110 mil offer Daren nearly closed earlier this month.

We're told the compromise was lower price, but Hef gets to maintain access to the home for the rest of his life. Bottom line: Daren can't pop over whenever he wants. However, as the new landlord ... he does get to approve all parties at the mansion.

Daren -- a master re-brander of products and the Pabst Blue Ribbon heir -- who's been living next door since 2009 has already given the thumbs-up to Playboy's Midsummer Night's Dream Party next Saturday ... and the annual Halloween bash.

We're told he plans to connect the adjacent home he owns with the Playboy Mansion and restore both estates to their original versions. Daren was represented by Coldwell Banker agent Jade Mills & Mauricio Umansky represented Playboy.