Catalyzes the transport of phospholipids such as phosphatidylethanolamine (1,2-diacyl-sn-glycero-3-phosphoethanolamine) and phosphatidylcholine (1,2-diacyl-sn-glycero-3-phosphocholine) between membranes. Required for the assembly and secretion of plasma lipoproteins that contain apolipoprotein B. a 1,2-diacyl-sn-glycero-3-phosphocholine(in) = a 1,2-diacyl-sn-glycero-3-phosphocholine(out) a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out)