US defence company Lockheed Martin says its incoming president and chief executive officer has resigned over a relationship with a subordinate.
It said Christopher Kubasik resigned after an ethics investigation confirmed the "close personal relationship".
Mr Kubasik, 51, was due to take over as head of the company next year after serving as its chief operating officer.
Lockheed Martin is a defence and aerospace company based in Maryland that employs some 120,000 worldwide.
Its net sales for 2011 were $46.5bn (£29bn).
Lockheed said in its statement that its board had "asked for and received" Mr Kubasik's resignation.
Chairman and outgoing CEO Robert Stevens said he was "deeply disappointed and saddened" by the relationship, which he described as "inconsistent with our values and standards".
But he said the company had a "strong leadership team and a robust succession plan".
Mr Stevens later told reporters on a conference call that the incident was a "temporary distraction".
Mr Kubasik said: "I regret that my conduct in this matter did not meet the standards to which I have always held myself."
Another Lockheed executive, 58-year-old Marillyn Hewson, will take over immediately as president and chief operating officer, and become CEO in January.