McMillan joined CMGI seven months ago as the company's chief financial officer and treasurer after a four-year stint with BMG Direct, a unit of Bertelsmann. The promotion becomes effective March 1.
Wetherell will remain chairman of the company's board of directors, providing counsel on CMGI's strategic initiatives. A company representative said the reason for the transition was "a function of the business itself" and "the board felt it was a good time given that we were coming out of a comprehensive restructuring."
The turnover closes a chapter for dot-com icon Wetherell, who transformed CMGI into a Wall Street darling during the late 1990s by making aggressive investments in a raft of Internet start-ups, including Engage, AltaVista, Equilibrium and uBid. The strategy helped raise CMGI shares to around $160 in early 2000, but the company's fortunes burst along with the bubble, trading at $1.37 late Tuesday.
Wetherell took a significant pay cut for 2002, slashing his annual salary from $530,000 to $1. According to a document filed last year with the Securities and Exchange Commission, the cut was a result of the company's "current state of unprofitability." Wetherell elected to forgo participation in the company's bonus plan, and he was granted a wide selection of stock options in the various companies owned or controlled by CMGI.
CMGI said McMillan has also been elected to the company's board of directors.
News.com's Margaret Kane contributed to this report.