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A new type of catalyst, a cobalt carbonyl-complex has been found for homogeneous hydroformylation. The complex has been prepared from Co2(CO)8and the ethylene glycol diester of 3-(2-pyridyl)propionic acid as a ligand. The catalyst is active even at the low temperature of 50 °C and very low carbon monoxide pressure range of less than 1 kg/cm2. On subsequent cooling it separates from the reaction product. The ligand was prepared by the hydroesterification of 2-vinylpyridine with carbon monoxide and methanol (or ethanol), followed by the trans-esterification with ethylene glycol. The effect of the partial pressures of carbon monoxide and hydrogen on the product composition and on the recovery of the catalyst was examined. The catalytic activity of the new complex is considerably higher than that of Co2(CO)8at a lower temperature. The selectivity to linear aldehyde in the presence of new complex is significantly higher than in the presence of Co2(CO)8when the hydrogen to carbon monoxide ratio (H2/CO) in gas phase is high, but this difference in selectivity is small when the above gas ratio is normal. The new complex can be applied as catalyst for removal of carbon monoxide in hydrogen by means of oxo process.