This invention relates to a series of novel late transition metal catalysts for olefin oligomerization, the catalysts demonstrating high activity and selectivity for linear α-olefins. The catalysts contain a Group-8, -9, or -10 transition metal, M, excluding palladium; an ancillary ligand comprising: a terminal amine comprising two independently selected hydrocarbyl radicals, R1 and R2; a terminal phosphine comprising two independently selected hydrocarbyl radicals, R3 and R4; and a hydrocarbyl bridge, Y, comprising a backbone wherein the hydrocarbyl bridge connects between the terminal amine and the terminal phosphine and wherein the backbone comprises a chain that is four or more carbon atoms long; and an abstractable ligand, X. For example this invention relates to a composition of matter with the following formula: wherein M, R1, R2, R3, and R4, Y, and X are as defined above.