Three years ago, Simon M. Schama was one of those professors who seemed destined for greatness.

A favorite among students with a growing international reputation among scholars, the European history specialist was among Harvard's most prized up-and-coming professors.

But when Schama's wife, Virginia E. Papaioannou, then an associate professor at Tufts, was offered a tenured job at Columbia in 1993, Schama agreed to leave his Harvard appointment to accept a position there.

"The way that worked out is they recruited me and once that was fairly far along in the process I let it be known that we were a two-career family," Papaioannou says. "It was pretty clear to Columbia that he was a prize catch."

The loss of Schama was not the first time Harvard lost a noted professor because his or her spouse had career possibilities in another city. Nor will it be the last.

In the increasingly competitive world of academic recruitment, an issue that was never a problem during the heyday of one-career families has come into focus as one of the most important challenges in recruiting new faculty members.

Over the past two decades, the percentage of two-career families in America has grown substantially. Today, 48 percent of all workers come from two-career families, up from 41 percent in 1980, according to the Bureau of Labor Statistics. The number is expected to top the 50-percent mark by the end of the century.

As a result of these societal changes, University recruiters are slowly discovering that they must adjust their strategies.

Persuading a well-known academic to move to the Boston area and join the ranks of the Harvard faculty becomes much more difficult when that professor has a spouse who is building momentum in a career, or is already established in a high-profile job.

Both faculty and administrators agree that the challenge of dealing with a two-career family is more than common and very important in the process of appointing new senior professors.

"It is no surprise that we are increasingly concerned about job opportunities for the spouses of faculty whom we are trying to persuade to come to Harvard," says Dean of the Faculty Jeremy R. Knowles.

Charles S. Maier '60, Krupp Foundation professor of European Studies and Director of the Gunzburg Center for European Studies, says he had been concerned with the problem in several recruiting searches for historians.

"They are probably one of the major challenges in recruiting the people you want to professorships," Maier says.

The necessity of thinking about spousal careers during the appointment process is a significant change from the past.

"In the days of one-career marriages, housing subsidies and contacts with schools were pretty much all you had to do, but to actually find employment for the recruited person's significant other is much more difficult and chancy," says William M. Todd III, chair of the Slavic Department and soon-to-be dean of undergraduate education.

Recruiting