Standard Life has been accused of breaching the takeover code after indicating it is looking at restructuring its bid for fellow insurer Resolution.
Standard Life said in a statement yesterday that it was exploring "a number of options for restructuring its proposed offer" for Resolution, which had earlier said it was no longer able to support the £4.9 billion bid in its current form.
Resolution said the offer was likely to be rejected by its largest shareholder, Pearl, which has teamed up with the Royal London Mutual Insurance Society to present a rival 720p-a-share bid for the insurer.
But last night the UK's takeover watchdog claimed Standard Life's statement in reaction to the move had breached section 19.3 of the takeover code, which states that "an offeror must not make a statement to the effect that it may improve its offer without committing itself to doing so and specifying the improvement".
"Standard Life has confirmed to the executive that there can be no certainty that Standard Life will ultimately be able to restructure its offer," the Takeover Panel added.
In a statement last week Resolution had confirmed that its board was withdrawing its support for the company's long-planned merger with Friends Provident in order to recommend the Standard Life offer which is backed by Swiss Re.
But Pearl, which owns a stake of around 24 per cent in Resolution, subsequently trumped Standard Life's bid with a fresh offer of its own.
While consequently withdrawing its recommendation of the Standard Life offer in its current form, Resolution stressed it continued to see "real strategic benefit" in a potential tie-up between the two insurers and that a restructured offer by its favoured suitor could prove attractive to its shareholders.