UK private equity fund Permira, owner of UK frozen food giant Iglo Group, could be the unknown second bidder for Cermaq's fish feed arm EWOS, reported Norwegian newspaper Finansavisen.

"Permira has already a solid experience in the seafood industry through its ownership of animal feed producer Provimi. Under Permira's four-year holding period the salmon-business was sold to BioMar," the newspaper wrote.

In 2011, the remaining Provimi shares were sold to US agricultural giant Cargill for $2.1 billion (€1.6 billion).

About three months ago, Permira bought the Norwegian salmon vaccine manufacturer Pharmaq for NOK 1.9