Gribbon, the latest to join an exodus of top officials from the world-renowned museum, announced Monday that she would leave at the end of the month.

"It has become increasingly clear that we differ on a number of critical issues," Gribbon wrote in a letter to Barry Munitz, president and chief executive of the J. Paul Getty Trust. The letter was obtained by the Los Angeles Times.

Gribbon and Munitz declined to specify the issues to the Times, but Munitz said there has been serious discussion about how much the trust spends on the museum and on other programs.

"We've been going through all summer what our priorities are and where the resources are. There's still an enormous commitment to the museum - the museum is the center and the core of what we do - but the board feels very strongly that it's not the only thing that we do," he said.

The trust also funds research and art conservation institutes and a research program, as well as the Getty Villa, a reproduction of a Roman villa that will house the Getty's Roman and Greek works when its long-overdue renovation is completed next year.

"I don't think it's a matter of personalities," former Getty trustee Rocco Siciliano said of Gribbon's exit. "It turns on finances. I think it's about a serious assessment that has been going on for a long time, about the future of the Getty and the budget for new acquisitions."

Gribbon, 56, joined the Getty as assistant director for curatorial affairs in 1984 after working as a curator at the Isabella Stewart Gardner Museum in Boston and the Boston Museum of Fine Arts.

William Griswold, the museum's associate director for collections, will become acting director and chief curator.

Gribbon replaced John Walsh, who was museum director from 1983 to 2000. Stephen Rountree, executive vice president and chief operating officer, and Barbara Whitney, associate director for administration and public affairs, also have left in recent years.

"People have been talking for a long time about how bad things were at the Getty," said Whitney, who left in August. "Part of the reason why I left was that the place had become totally internally focused, with a lot of intrigue about who was in or out of favor."

The Associated Press