With less than half of the notes tendered so far, the Russian owner decided to give investors until 8 May to decide on a sale.

So far, $128.6m of the 2018 notes and $88.9m of the 2020 notes have been tendered, the company said.

It also made good on its promise to repurchase $130m of its debt, up from the $85m that was previously announced.

Fesco