Polymerization process for producing ethylene based polymers

A polymerization process for producing ethylene based polymers comprising:

• polymerizing ethylene and optionally one or more α-olefins in the presence of one or more first catalyst systems and optionally one or more second catalyst systems in a dual reactor system or a multiple reactor system, wherein first catalyst system comprises;
• (a) one ore more procatalysts comprising a metal-ligand complex selected from the group consisting of
• and
• (b) one or more cocatalysts;
• wherein the ratio of total number of moles of the one or more metal-ligand complexes of formula (I) to total number of moles of the one or more cocatalysts is from 1:10,000 to 100:1.