THE chief executive of NatWest's investment banking arm has resigned, the banking group announced yesterday as it issued a profits warning.

The decision by Mr Martin Owen, who has been chief executive of NatWest Markets since 1992, followed a £77 million sterling loss suffered by the group earlier this year on complex interest rate deals.

Mr Derek Wanless, the group's chief executive, has taken over responsibility of the division as acting chief executive. He is to continue managing the investment banking business until a new chief executive is appointed.

At the same time, the group is carrying out a review of NatWest Markets to speed up progress towards "acceptable returns" in key business areas and to ensure the improvement in controls and risk management.

Mr Wanless commented: "The review at NatWest Markets had already been initiated by Martin Owen and his executive team and I will take this forward.

"Our focus will be on areas where we have a competitive advantage with a strong product or research base".

The group also announced that an independent inquiry into the black hole caused from the huge losses run up involving complicated financial dealings with interest rate options announced earlier this year, was nearing completion.

The main findings of the report will be announced before the end of June.

The investigation has already confirmed that the net charge against profits is unchanged at £77 million.

But NatWest warned that the incident had had a knockon effect on the profits of Nat West Markets and for the first half of 1997, profits at the investment banking arm, were expected to be significantly lower than the corresponding period last year.

"As a result, the pretax profits of the NatWest Group are not expected to exceed £770 million for the first half of 1997, subject to any unforeseen circumstances."