A process for producing linear aldehydes or alcohols from olefins using a transition metal hydroformylation catalyst wherein the catalyst comprises an anionic transition metal catalyst wherein the transition metal is Fe, Ru or Os and the catalysts generally have a charge of at least -2. The formula of the anionic catalyst is generally defined as M.sup.+n [H.sub.y A.sub.x L.sub.z ].sup.-n wherein A represents Fe, Ru or Os, M is a cationic species, n is an integer greater than or equal to 2, x is an integer greater than or equal to 1, y is an integer greater than or equal to 0 and z is an integer generally corresponding to the number of available coordination bonding sites in the ruthenium complex. Monoanionic osmium catalysts are also included within the present invention. These hydroformylation catalysts exhibit greater selectivity toward straight chained aldehydes and alcohols than anionic catalysts having a charge of -1 or a neutral catalyst. The monoanionic osmium catalyst also exhibits an increased selectivity toward the straight chain product.The novel hydroformylation catalyst of the present invention is also disclosed.