A catalyst composition and method for olefin polymerization are provided. In one aspect, the catalyst composition is represented by the formula .alpha..sub.a.beta..sub.b.gamma..sub.gMX.sub.n wherein M is a metal; X is a halogenated aryloxy group; .beta. and .gamma. are groups that each comprise at least one Group 15 atom; .alpha. is a linking moiety that forms a chemical bond to each of .beta. and .gamma.; and a, b, g, and n are each integers from 1 to 4.