Triply-bridging bis-{hydrido(borylene)} and bis-borylene species of groups 6, 8 and 9 transition metals are reported. Mild thermolysis of [Fe₂(CO)₉] with an in situ produced intermediate, generated from the low-temperature reaction of [Cp*WCl₄] (Cp*=η⁵-C₅Me₅) and [LiBH₄⋅THF] afforded triply-bridging bis-{hydrido(borylene)}, [(μ₃-BH)₂H₂{Cp*W(CO)₂}₂{Fe(CO)₂}] (1) and bis-borylene, [(μ₃-BH)₂{Cp*W(CO)₂}₂{Fe(CO)₃}] (2). The chemical bonding analyses of 1 show that the B−H interactions in bis-{hydrido (borylene)} species is stronger as compared to the M−H ones. Frontier molecular orbital analysis shows a significantly larger energy gap between the HOMO-LUMO for 2 as compared to 1. In an attempt to synthesize the ruthenium analogue of 1, a similar reaction has been performed with [Ru₃(CO)₁₂]. Although we failed to get the bis-{hydrido(borylene)} species, the reaction afforded triply-bridging bis-borylene species [(μ₃-BH)₂{WCp*(CO)₂}₂{Ru(CO)₃}] (2′), an analogue of 2. In search for the isolation of bridging bis-borylene species of Rh, we have treated [Co₂(CO)₈] with nido-[(RhCp*)₂(B₃H₇)], which afforded triply-bridging bis-borylene species [(μ₃-BH)₂(RhCp*)₂Co₂(CO)₄(μ-CO)] (3). All the compounds have been characterized by means of single-crystal X-ray diffraction study; ¹H, ¹¹B, ¹³C NMR spectroscopy; IR spectroscopy and mass spectrometry.