Aside from Ferenginar, have the Ferengi ever settled or occupied planets from other systems in large numbers?
The most clear canonical example is Lappa IV. From the transcript for "Ménage à Troi" :
WORF: When you have finished here, survey in that direction.
CREWWOMAN: Aye, sir.
GRAX: I wish I had some answers for you, Lieutenant Worf.
WORF: Mister Homn was no help? GRAX: None. He last saw them as he was leaving this clearing. When he returned, all three of them were gone.
DATA: Lieutenant Foley discovered this in the pond. (Tog's bouquet) The species is Zan Periculi. It is not indigenous to Betazed, but to Lappa Four. A Ferengi world.
There are several other examples, as list on the list of Ferengi planets1, but they are more ambiguous. For example, Volchak Prime has ports that are owned by Ferengi:
QUARK: Is something wrong?
KRAX: You can't seat Turot next to Hoex. They've been bitter rivals ever since Hoex bought out Turot's controlling interest in the cargo ports on Volchok Prime.
However, this does not necessarily imply that the planet is under the control of the Ferengi alliance, merely that certain Ferengi do business there.
1. Credit to @Valorum