Fortress Investment Group, a US alternative assets manager, is set to buy Telent, the remaining part of former UK telecoms equipment company Marconi, in a deal worth £346m (€507m).

Telent said that it would accept an offer of 529.5p a share from Holmar, a Fortress investment vehicle. The offer, which would represent a 13.3% premium on yesterday's closing share price, is subject to Holmar confirming that existing contracts will not be affected by the change in ownership.