Openly gay applicants are 40 percent less likely to be granted an interview than their heterosexual counterparts, according to a study published Tuesday in the American Journal of Sociology.

The study was the first large-scale investigation to test the receptiveness of employers to gay male job applicants. Similar studies have been conducted to expose hiring prejudice based on race or sex.

"The results indicate that gay men encounter significant barriers in the hiring process because, at the initial point of contact, employers more readily disqualify openly gay applicants than equally qualified heterosexual applicants," wrote the study's author, Andras Tilcsik of Harvard University.

Discrimination against openly gay candidates was particularly strong in Southern and Midwestern states.

Tilcsik sent two fictitious but realistic resumes to more than 1,700 entry-level, white collar job openings across the United States. The resumes were nearly identical, except for one small difference -- one mentioned that the applicant had been part of a gay organization in college, while the other did not.

"I chose an experience in a gay community organization that could not be easily dismissed as irrelevant to a job application," Tilcsik explained. "Thus, instead of being just a member of a gay or lesbian campus organization, the applicant served as the elected treasurer for several semesters, managing the organization's financial operations."

The other resume mentioned that the applicant had been part of the "Progressive and Socialist Alliance" instead of a gay organization. The fictional group was used to separate any "gay penalty" from the effects of political discrimination, since both organizations were likely to be viewed as left-leaning.

In addition, employers seeking stereotypically masculine traits, such as assertiveness, were more likely to discriminate against gay men.

"It seems, therefore, that the discrimination documented in this study is partly rooted in specific stereotypes and cannot be completely reduced to a general antipathy against gay employees," Tilcsik said.

There is no federal law that protects gay individuals from employment discrimination, and only 21 states have laws that prohibit discrimination in the workplace based on a person's sexual orientation.