Secure Computing today named Daniel Ryan as interim CEO. He replaces John McNulty, who served as board chairman and CEO since 1999.

Ryan has served as the company’s president and chief operating officer since last August. Richard Scott, a Secure Computing board member since January 2006, was appointed chairman. McNulty will continue as a board member.

The San Jose-based vendor, which makes Web security gateways and other products, didn’t explain why McNulty is stepping down. A call to a company press contact was not immediately returned.

McNulty’s tenure included Secure Computing’s $274 million acquisition of email security vendor CipherTrust in 2006, which closely followed its $295 million acquisition of CyberGuard. Scott was a CyberGuard board member.