Method for oligomerization of ethylene

A method for oligomerization of ethylene, comprising the steps:

• a) feeding ethylene, solvent and a catalyst composition comprising catalyst and cocatalyst into a reactor,
• b) oligomerizing ethylene in the reactor,
• c) discharging a reactor effluent comprising linear alpha-olefins including C6+ linear alpha olefins and 1-butene, solvent, unconsumed ethylene dissolved in the reactor effluent, and catalyst composition from the reactor,
• d) separating ethylene and 1-butene collectively from the remaining reactor effluent comprising the C6+ linear alpha olefins, and
• e) recycling at least a part of the ethylene and the 1-butene separated in step d) into the reactor;
• and
• wherein a constant 1-butene content is in the reactor.