Tom Hogan was formerly vice president of sales at customer relationship software maker Siebel. President and Chief Operating Officer Paul Wahl will continue to run Siebel's sales operations, the company said in a statement.
Siebel shares dropped $3.75, or 11.15 percent, to $29.88 Tuesday morning. Vignette shares rose sharply, gaining $1.33, or 26 percent, to $6.54.
Hogan's resignation is "clearly not a positive announcement," said Brent Thill, an analyst at Credit Suisse First Boston, who cut his profit outlook for Siebel, Bloomberg News reported.
Hogan will assume responsibility for worldwide operations, including sales, marketing, support, services and product development, at Vignette, the company said.
Mountain View, Calif.-based Vignette makes publishing and personalization software for e-commerce companies and competes with BroadVision. In January, Vignette announced plans to shut some offices and trim its work force by approximately 15 percent to reduce expenses as it prepared for weaker earnings.