Anionic polymerization of methyl methacrylate (MMA) in the presence of divalent transition metal halide (MX2 = FeBr2, MnCl2, CoCl2, NiBr2) was investigated. Initiating systems with various combinations of MX2, lithium diphenylamide (Ph2NLi), and organolithium (RLi, where R = nBu, Me) were effective to giving a high yield of poly(methyl methacrylate)s (PMMAs) at -78 degreesC in toluene. The tacticity of the resulting PMMAs was highly dependent on the combination of the reagents used for the generation of the initiating systems within a syndiotactic (rr = 59%) to isotactic (mm = 65%) range. (C) 2003 Wiley Periodicals, Inc.