John Fredriksen-led Seadrill has engaged DNB Markets to explore the purchase of almost 117 million Sevan shares to give it 50% of Sevan.

The price it is offering is Nkr 3.95 ($0.65) a share.

However, Seadrill also signaled its intention to chase 50.1% of Sevan which would then give it full control.

The move is being made in response to a financing plan revealed by Sevan on 19 June where it plans to issue $500m in senior secured bonds and finalise a $1.45bn corporate bank facility to refinance outstanding debt.

“Seadrill is of the opinion that the financing plan proposed by Sevan … is value destructive for the shareholders,” Seadrill said in an Oslo bourse announcement late on Wednesday.

“Subject to a completion of the proposed share purchase Seadrill will seek to propose an alternative and improved financing structure.”

If Seadrill does get its hands on 50.1% of Sevan it said it could call an extraordinary general meeting where it would propose a new board.

If it fails, however, it will consider selling off its entire 30.4% in Sevan.

In January Seadrill sold all its shares in Sevan – then 28.52% - but struck a forward agreement to buy them all back at a strike price. This kept Seadrill’s foot in the door in terms of a possible takeover.

Seadrill’s holding had theoretically moved up to 30.31% in early January following an emergency equity issue from Sevan to plug a funding gap.

Oslo-listed Sevan successfully raised Nkr987.5 million ($177.4 million) in the private placement, which was oversubscribed, at a price of Nkr3.95 per share.

This brought Seadrill perilously close to the 33.3% ownership threshold that would have required a mandatory takeover offer to be launched under Oslo Stock Exchange regulations.

Sevan secured waivers from banks on loans for its operating rigs Sevan Driller and Sevan Brasil until the end of February, while also gaining beneficial amendments to the loan agreements to lessen the financial strain and a low interest rate.

The cylindrical units have proven a cash drain on the company as lower utilisation rates have hit dayrate earnings, leading to a cash shortfall of $154 million for the special-purpose vehicles set up to own the pair that has had to be covered by parent Sevan.

In particular, the newbuild Sevan Brasil was hit by an issue with its blowout preventer last year that had to be repaired, leading to a reduced dayrate for the unit shortly after being delivered.

Sevan is also expecting delivery of two further units: the first of the replica ultra-deepwater rigs, being built at a cost of $526 million apiece at China’s Cosco Shipyard, is scheduled for delivery in November with the second due to exit the yard in April 2014.