Catalyzes the polymerization of lipoteichoic acid (LTA) polyglycerol phosphate, a reaction that presumably uses phosphatidylglycerol (PG) as substrate. Cell wall biogenesis; lipoteichoic acid biosynthesis. The secretion into the extracellular medium is dependent on SecA and Ffh. Transcribed under partial control of SigM ECF sigma factor (PubMed:17434969). Proteolytically cleaved by the type I signal peptidases SipT and SipV. Could not restore staphylococcal growth after ltaS depletion. Belongs to the LTA synthase family. Extended N-terminus.