Matthew Perry -- Trying to Unload ANOTHER L.A. Home

Matthew Perry seems determined to downsize his Los Angeles real estate portfolio -- the actor just listed his Modern-style hilltop estate for $5.695 million.

In case you're keeping track -- this is the third crib Matt's tried to unload in the last two months -- he listed a condo in the posh Sierra Towers in August, and his Malibu beach pad just a few weeks ago.

The new listing comes in at a spacious 4,100 square feet -- and has 3 bedrooms, 4 bathrooms, a media room ... and walls of windows to show off the smoggy view of downtown L.A.