"I've been doing this for 15 years. I think I deserve a break," Schrock said in an interview. "I honestly will spend six to 12 months with my family."
Greg Memo, AltaVista's chief operating officer, and Ken Barber, its chief financial officer, will share responsibilities while the company searches for a new CEO.
Schrock, a former executive at Compaq Computer, was tapped by the company to run AltaVista in January 1999. Compaq gained control of the search engine after it acquired AltaVista's parent company, Digital Equipment, in 1998.
Schrock continued at his post when CMGI acquired AltaVista in June 1999 for $2.3 billion.
Schrock's resignation is the latest setback for AltaVista. The company has weathered corporate takeovers and strategic shifts in the last few tumultuous years. Schrock said the company has been a victim of bad timing and corporate neglect since its inception.
"Digital (Equipment) failed to invest in AltaVista during the first three years on the Internet," Schrock said. "It's fair to say that AltaVista's historical sense of timing has been the worst."
In April, AltaVista delayed its initial public offering after the market for Internet stocks took a nosedive. Then in September, the company slashed its work force by 25 percent in an effort to focus on Web search technology and hasten profitability.
AltaVista previously had tried to adjust its business to the changing tides of the market. Months after acquiring it, CMGI launched a $120 million advertising campaign to re-brand the site as a major Web portal capable of taking on Yahoo and America Online. That turned out to be an expensive attempt to catch industry leaders already outpacing their rivals.
Eventually, AltaVista decided to step back to its Digital Equipment roots and focus on its search technology. Long considered a pioneer search engine on the Web, AltaVista hoped to become a challenger to popular rival search services such as Google and GoTo.com. In May, it launched Raging Search, a streamlined search engine, to compete with Google.