The president of Chatham University's 11,000-member alumni association has asked the school to delay a potential May vote on a controversial proposal to let its 145-year-old women's undergraduate college go coed.

Gail Ruszczyk said in a letter to leadership of Chatham's board of trustees that requested data and information from the school that would help the group and its members better understand the situation "have not been provided in a timely manner." The letter from Ms. Ruszczyk, who also is a trustee, was made public late Monday on the eve of a second forum for alumnae that Chatham has decided will be closed.

Ms. Ruszczyk said a decision should be delayed until fall.

A two-page list of questions that accompanied the March 4 letter to board chairwoman Jennifer Potter asked for copies of review materials including what other options were explored and why they were rejected. It noted that discussions about the college's future were apparently underway for six months before the Feb. 18 announcement that trustees would vote by June on whether to allow men to enroll starting in fall 2015.

"Why didn't the Chatham University board of trustees or the Chatham University administration inform the [alumni] board that this [coed option] was under discussion?" the association's correspondence asked.

Chatham spokesman Bill Campbell said the board is preparing a response. Also Monday, Mr. Campbell said the university will not allow outsiders including the media inside tonight's 6 p.m. session in Eddy Theatre on the Shadyside campus. Asked the reason, Mr. Campbell said Chatham last week "decided to make an exception" by inviting in the broader community but now wants to have a conversation with just its constituents. Only graduates, students and employees will be allowed in the room.

Asked about alumnae calls for open sessions, Mr. Campbell noted there are thousands of Chatham graduates, adding: "The opinions of a few are not necessarily representative of what everybody is thinking."

Alexa New, a spokeswoman for graduates trying to preserve the single-sex college, expressed disappointment at the decision. "What we've heard is there are many alumnae who are still not aware of the decision. The notification process ... has been a little disappointing," she said. "Having open discussions about this is critical, and media are at least helping us to spread the word."

First Published: March 11, 2014, 3:01 a.m.