VeriSign

(VRSN) - Get Report

said today that former

Network Solutions

Chief Executive James Rutt will leave the company April 1.

VeriSign recently acquired Network Solutions. Senior executives in the mass market and enterprise divisions will take on Rutt's former responsibilities. The company, a provider of Internet security services, hasn't yet released the name of the new chief executive.

Rutt plans to research complex adaptive systems and hopes to publish a peer-reviewed paper with in two years. He will consult for the combined company until he leaves VeriSign.

Shares of VeriSign, which is based in Mountain View, Calif., gained $3.94, or 8.1%, to $52.94 in recent

Nasdaq

trading.