Commonwealth Bank has agreed to sell its stake in Chinese life insurer BoComm Life for $668 million.

CBA needed to offload the 37.5 per cent stake as a condition of its $3.8 billion deal to sell its local life insurance businesses to AIA, and will sell to Japan’s Mitsui Sumitomo.

The proceeds will be used by CBA to lift its Common Equity Tier 1 ratio by 0.13 percentage points.

The move is part of a divestment program that began under former chief executive Ian Narev and has continued under his successor, Matt Comyn.

“This transaction represents a further step in simplifying and focusing our portfolio,” Mr Comyn said on Wednesday.

CBA is also aiming to spin off its global asset management business by the end of 2018.

CBA shares were down 35 cents, or 0.5 per cent, at $69.90 at 1310 AEST.