For nearly 13 years Jane Welch stood by her husband, Jack, the now-retired chairman of GE, through two heart attacks, a quintuple bypass and countless bare-knuckled corporate dustups. Last week she apparently found the limit of her ability—or willingness—to cope. Within days of the embarrassing public disclosure of her husband's affair with Suzy Wetlaufer, 42—a Harvard Business Review editor who confessed to getting "too close" to Welch while interviewing him for a story—Jane, 49, hired a lawyer to start the process rolling toward a financial settlement and divorce from the 66-year-old magnate.

News of the extramarital relationship, and subsequent split, surprised most of those close to the couple. "It was a very sad day for me to see this happen," says pal Donald Trump, one of many who regarded the tycoon and Jane—an Alabama-born securities lawyer Welch met six months after his 1987 divorce from first wife Carolyn—as a perfect partnership. However, friction appears to have increased after Welch's retirement from GE in September. "Jane really hoped that he would slow down," says a friend. "He continued to push ahead at 100 mph."

Money should not be a concern for Jane. Her prenup with Welch has expired, so she can claim a share of his estimated half-a-billion-dollar fortune. As for Wetlaufer, the recently divorced mother of four stepped down from her $277,000-a-year job at the Review when word of the relationship first leaked. But she will rejoin the staff as an editor-at-large. And indications are that she may continue to light up Welch's life. "He is serious. Definitely," says a close friend. "He wouldn't be going through all this if he weren't."