IBM is suing another one of its former executives to stop him from going to a competitor.

This time it's former M&A chief David Johnson who's bound for Dell. Last time it was chip guru Mark Papermaster after he was hired by Apple to be head of iPod and iPhone engineering.

IBM is standing on the non-compete Johnson signed in 2005 and accuses him of misappropriating its trade secrets. Sounding just like the suit against Papermaster, the complaint against Johnson says the information he possesses is "among the company's most competitively sensitive information, is carefully guarded, not made accessible to the public or IBM's competitors, and is disclosed even to IBM employees on a strict ‘need to know' basis."

Johnson knows what companies and technologies IBM plans to invest in, when, what ROI it expects and what it may divest.

IBM says Dell, which isn't named in the name, hired Johnson to be its senior VP of strategy, which IBM figures is another way of saying its M&A guy.

Its suit claims that "Mr. Johnson, as long as he is employed by Dell, will inevitably use and/or disclose IBM trade secrets for his own benefit and for the benefit of Dell."

Of course, Dell has historically been pretty thin on M&A so the move suggests it's going to try another way of digging out of the hole it's in. It has $9 billion in the bank.

IBM was able to keep Papermaster on the bench for six months before settling for a proviso that he certify in July and again in October that he has not used or disclosed IBM confidences. If he has any doubts he has to check in with IBM.