County Natwest, adviser to Amec, fears Kvaerner may be in breach of the takeover code when it publishes the terms of its offer to preference shareholders.
Kvaerner has mounted a pounds 202.6m cash bid for the ordinary shares, but has until Monday to detail the terms of its offer for the large number of preference shares in issue, worth about pounds 172m.
The warring sides held a secret meeting on Wednesday at which Kvaerner is thought to have suggested that Amec recommend the offer in return for favourable treatment for the preference shareholders. Under takeover rules, the preference shares terms cannot be much different from Kvaerner's pounds 1- a-share bid for the ordinary capital. Amec fired its first formal shot against Kvaerner yesterday, detailing why it believes the bid undervalues the UK firm. Amec said shareholders should be aware that Kvaerner is particularly interested in Amec's Process and Energy activities.