The Phi Beta Kappa chapters of Harvard and Radcliffe, which currently select members separately, are close to ratifying a constitution that will merge the two chapters of the academic honor society, members said yesterday.

The single-sex chapters currently select equal numbers from separate pools of male and female students. If the new constitution is ratified, members will be selected into one co-ed chapter from a unified pool of students.

Student and graduate members expressed support for the unification of the two chapters.

"Since the schools are merged, the chapters should be merged as well," said Lila M. Guterman '95, a member of the Iota Chapter, the group for women.

In addition, the chapters have experienced pressure to merge from the national Phi Beta Kappa organization, said Daniel Steiner '54, former general counsel for the University and president of the group's Alpha Chapter, which is composed of men.

The new system calls for candidates to be grouped by field of study rather than by gender during the selection process.

Three subcommittees--in the natural sciences, social sciences and humanities--would select members from among the candidates in their fields, said Professor of English and Comparative Literature James T. Engell '73, who is vice president of the Alpha Chapter.

Benjamin C. Sun '95, a Phi Beta Kappa member, said the proposed method makes more sense.

"Most of the people have been in the sciences," Sun said. The proposed method would ensure appropriate representation for students of the humanities, where grading is more subjective, he said.

If the new joint constitution is approved at the chapter meetings on November 17, it will take effect after Commencement this June, said Elisabeth W. Swain '63, president of the Iota Chapter.

The two chapters will also vote at that meeting on a new set of by-laws calling for a different selection process, Engell said.

Phi Beta Kappa accepts 24 juniors in the spring on the basis of grade point average and "depth and breadth of study as indicated by curriculum and by letters of recommendation," Steiner said.

The organization uses the same criteria to accept another 48 members from the senior class in the fall and then, before commencement, approximately the top 10 percent of the class.