For at least another semester, Yale will host no more than three sororities.

Last spring, the Yale Panhellenic Council sought to begin a process known as “extension” — the introduction of a new sorority to the University — to help accommodate the growing number of female students interested in Greek life at Yale. But the National Panhellenic Conference has said Yale’s three sororities must roughly equalize their membership before a fourth sorority can arrive on campus. Though Yale Panhel officers had hoped to even out the sororities’ enrollments by this fall, Kappa Kappa Gamma is still trailing its peer organizations in membership, and Yale Panhel President Stephanie Cuevas ’12 said getting Kappa caught up may take another year or two.

National Panhellenic Conference’s College Advisor for Connecticut Patricia Disque said in a email to the News Tuesday that in order for Yale Panhel to begin the process of extension, officers of the organization must demonstrate that another sorority could survive on campus. The conference would look for membership statistics and numbers from Yale’s past rush processes that evidence a strong campus interest in Greek life. After it has been determined that a new sorority could survive, bringing one to Yale could take another six months to two years, Disque added.

“Part of the reason [a fourth sorority] is a pertinent issue now is that the interest in sororities has been increasing consistently in the past years,” Cuevas said.

Because Kappa currently lags behind the other two sororities in membership, it was allowed to carry out informal recruitment for the fourth year in a row this fall to level the playing field — a process distinct from the official rush period that all three sororities hold during the spring semester, Cuevas said.

Kappa gained 22 new members through this additional recruitment opportunity, growing to 96 members but remaining far behind Kappa Alpha Theta’s 117 and Pi Beta Phi’s 108.

Last January, 205 women enrolled in the sorority rush process. Though Pi Phi and Theta each offered 46 bids and saw all of them accepted, Kappa retained only 30 of 40 rushees who had been offered spots.

The National Panhellenic Conference told Yale Kappa President Rachael Styer ’12 that the organization is working on recruitment efforts that could help the campus chapter close its membership gap.

“The campus Panhellenic and the chapter are focused on planning a successful winter recruitment and will reevaluate the need for extension later in the spring,” the conference wrote in a Tuesday email to Styer.

Panhel first considered introducing a fourth sorority to campus about a decade ago, Cuevas said, but the yearly changes in official leadership of the organization have hindered Panhel’s ability to make significant progress on the issue. The extension process at Yale might benefit from the presence of a campus Panhellenic adviser, a position that exists at most colleges nationwide, Cuevas added.

“Because there has not been an adviser, there has been very little continuity from year to year and the officers end up reinventing the wheel continuously,” Disque said.

In pursuing a fourth sorority, Panhel hopes both to accommodate more female students interested in Greek life and to decrease the size of incoming pledge classes for existing sororities, Cuevas said. The logistics of such large groups makes it difficult to find spaces on campus large enough to meet, she added.

Yale chapter sororities with fewer than 111 members may hold informal recruitment sessions in the fall.