This invention relates to a process for converting ethylene to a mixture of 1-olefins by (a) feeding ethylene through an oligomerization catalyst bed to form an oligomer predominating in C2-C6 olefins and (b) feeding the oligomer, optionally admixed with fresh ethylene, containing at least 50 % by volume ethylene, through a metathesis catalyst bed to form a product predominating in C2-C6 1-olefins. Steps (a) and (b) can be carried out sequentially and in a single reactor under the same conditions of reaction temperature and pressure. This mitigates the perceived disadvantages of low activity and low conversions of relatively inexpensive oligomerization catalysts and forms oligomer having the desired distribution of 1-olefin components for use as comonomer in a polyolefin process.