John Bethell, editor of the bimonthly Harvard Magazine, will leave his executive post to become the publication's senior editor.

Bethell will work on a book project for 1998 to commemorate the magazine's 100th anniversary.

The magazine's board of directors has organized a search committee to select Bethell's replacement, according to a University press release. Bethell will not begin his new position until a successor is found.

The committee is made up entirely of current directors of the magazine: Bill Kovach, curator of the Nieman Foundation; Thomas Reardon, director of University Development; David Ives, president of Harvard Magazine, Robert Shapiro, a partner in the Boston law firm of Ropes & Gray; and Theda Skocpol, professor of sociology.

Bethell, who became editor of the magazine in 1966, made major changes in the publication, which at the time of his appointment was available only by subscription.

Today the magazine, which has a circulation of more than 220,000 and is editorially independent of the University, relies on the University for its funding.