The former director of gay, lesbian, bisexual and transgender services at the University of Minnesota Duluth is suing, saying the school retaliated against her for protesting its treatment of gay coaches.

Angela Nichols resigned last September after a long-running dispute over the university’s decision not to renew the ­contracts of Shannon Miller, head coach of UMD’s winning women’s hockey team, and three other openly gay staff.

When Nichols protested the decision, she said, workplace relationships turned chilly, then hostile. Her colleagues retaliated against her, the suit claimed, and created a workplace “designed to force [her] to resign.”

Her lawsuit, filed Wednesday in Hennepin County District Court against the University of Minnesota Board of Regents, asks for more than $50,000 in damages. UMD also faces discrimination lawsuits from Miller, former women’s hockey director of operations Jen Banford, and former women’s basketball coach Annette Wiles.

The university is fully prepared to dispute the allegations, said UMD director of marketing Lynne Williams. UMD, she said, “remains unconditionally committed to providing a positive and inclusive campus. It is a fundamental value of our campus."