In an effort to draw more pledges and to dispel its perceived stereotype as exclusive, Sigma Alpha Mu fraternity members said yesterday they have sent letters to every male first-year student inviting them to participate in the group's initiation process.

"Fraternities have had a rap of being an elitist group," said Alan Lefkowitz, head of Sigma Alpha Mu. "I would hope that this [letter campaign] breaks down some of those feelings."

In the letter, which was sent to nearly 850 students, members of Sigma Alpha Mu--commonly known as "Sammy"--said the club will likely accept about 90 percent of those interested in joining.

After the fraternity was founded last fall, it came under fire for allegedly being an elitist social club limiting its membership to Jewish students. Although the club's founders were predominantly Jewish, officers said the stereotype was inaccurate, and that the large number of Jewish members was not planned.

"There happen to be a large number of Jewish people in our fraternity," said Jon L. Brisman '90, founder and former head of the fraternity. "A large part of the reason is that many of my friends were Jewish and more likely to join because they were my friends."

"What we had in mind was a fraternity, nothing more, nothing less," said Sandy J. Roskes '92 who chairs the fraternity's committee on rushing.

Founding members said they chose to start a chapter of the fraternity because they had received enthusiastic support from the Sigma Alpha Mu national headquarters and because of the fraternity's emphasis on public service.

Last semester, the Harvard Sigma Alpha Mu chapter sponsored a bowl-a-thon to raise money for cerebral palsy research and held a fund-raiser for the poor in Roxbury, according to the letter to first-year students.

But some of the students involved in forming the chapter at Harvard said they had been concerned about the negative stereotype of the fraternity. They noted that Sigma Alpha Mu chapters at other colleges are known for having a predominantly Jewish membership.

"When it was in its embryonic stages, some of the founding members thought that it would be a good idea for Sigma Alpha Mu to be a social organization for Jews," said David N. Gerschfield '90 who decided not to join the club.

Roskes, who coordinates the fraternity's rush, or initiation process, said Sigma Alpha Mu's traditionally Jewish affiliation had been a factor in some members decisions to enter the group, but that the fraternity is not intended for only Jewish members.

"I think a lot of people who decided to join were attracted to the fact that many of their brothers would be Jewish," Roskes said. "At this point, I don't see any reason that the fraternity remain primarily Jewish."