Heterotrimetallic compounds Mo2Ru(dpa)(4)Cl-2 (1) and W2Ru(dpa)(4)Cl-2 (2) are prepared by reactions of M-2(dpa)(4) (M = Mo or W; dpa = 2,2'-dipyridylamide) with [Ru(CO)(3)Cl-2]2 Crystallographic studies reveal short Mo-Ru and W-Ru distances, 2.38 angstrom (1) and 2.39 angstrom (2), suggestive of delocalized Mo-Mo-Ru and W-W-Ru bonding. In contrast to the sigma bonding found in the corresponding iron compounds, density functional theory calculations reveal both a three-center/two-electron s bond and two three-center/four-electron p bonds in the M-M-Ru compounds.