Catalyzes the formation of fatty acid-cholesterol esters, which are less soluble in membranes than cholesterol (  , ). Plays a role in lipoprotein assembly and dietary cholesterol absorption (, ). Utilizes oleoyl-CoA ((9Z)-octadecenoyl-CoA) preferentially as susbstrate: shows a higher activity towards an acyl-CoA substrate with a double bond at the delta-9 position (9Z) than towards saturated acyl-CoA or an unsaturated acyl-CoA with a double bond at the delta-7 (7Z) or delta-11 (11Z) positions (, ).
Subcellular locations: Endoplasmic reticulum membrane