Andreas Sohmen-Pao’s BW Group is launching an offer for subsidiary BW Energy, raising the prospect of yet another BW company being delisted in Oslo.

A stock exchange filing reveals that BW Group bought 250,000 shares on Wednesday in the oil exploration and production company for around NOK 5.9m ($558,000).

BW Group now has 40% of the company, the level at which a mandatory offer must be made.