Two black women who worked as security supervisors at Madison Square Garden are set to hit their former employer with a discrimination lawsuit, claiming they were denied advancement while young white interns who slept with management quickly rose to the top.

“It’s definitely a boys’ club there,” charged Diane Henson, 50, who said she worked at the Garden for 11 years only to get pushed out this summer once she complained about the unfair treatment of blacks, and women in particular.

Henson and a second woman participating in the lawsuit – who asked that her name be withheld – claim they were forced to resign after their complaints about discrimination were met with retaliation, an atmosphere they blame on Garden boss James Dolan.

When it comes to Dolan, employees are taught to live in fear, the women said.

“We were told, ‘Don’t look at him. You’ll get fired,’ ” Henson said.

Henson and her former co-worker described the discrimination they endured in an interview with The Post just days after a Manhattan federal jury awarded former Knicks executive Anucha Browne Sanders a stunning $11.6 million for sexual harassment and retaliation by the Garden organization and Dolan.

Another former Garden employee, Ranger City Skaters captain Courtney Prince, is also pushing forward with a sexual-harassment suit.

Henson said that during her first nine years at the Garden, she received regular raises and promotions. But when the new vice president of event operations, Kirk Randazzo, took charge in 2005, the writing was on the wall, she said.

“I didn’t seem to get the same opportunities everyone else got,” Henson said.

“It’s because we’re women and we’re black,” said the second woman, who is in her 50s and who worked at the Garden for five years until she quit last month.

Both women said they were relegated to posts in the nose-bleed sections of the Garden and areas with high rates of security problems, while their white – and in some cases less experienced – counterparts got plum positions in high-visibility sections where celebrities sit.

The women’s repeated requests for promotions were denied.

Meanwhile two female interns, who were white and in their 20s, had “open affairs with managers” and were quickly promoted, Henson said.

Soon, the two women’s bosses were writing them up for every minor infraction – ranging from tardiness to singing on the job, they said.

MSG officials declined comment on the charges, saying they were unaware of a possible lawsuit.

kati.cornell@nypost.com