Halle Berry -- Secretly Selling Hollywood 'Fight House'

Halle Berry has VERY quietly listed her Hollywood Hills mansion for $15 million ... the same home where Gabriel Aubry and Olivier Martinez faced off in a violent Thanksgiving Day showdown ... TMZ has learned.

Multiple real estate sources familiar with the deal tell TMZ ... a few weeks back Halle gave a prominent realtor a pocket listing -- a fancy term for property that isn't advertised. The broker -- Billy Rose with the high-end company, The Agency, has history with the house. He owned it a decade ago, renovated it and then sold it to actor Frankie Muniz, who sold it to Halle several years later.

Sources tell TMZ ... Rose has quietly put out feelers to other realtors and potential buyers ... with some success. We're told last week Halle got an $11 million offer, but she's holding out for more.

In case you're in the market, it's a 5-bedroom, 5,900 sq. ft. Tuscan-style estate, with a huge backyard, a 1,400 sq. ft. guest house ... an awesome pool and spa ... fireplaces galore ... incredible landscaping ... and oh yeah, a motor court -- where Gabriel and Olivier settled their score.