An ABC News staffer claimed the network retaliated against her after she filed a complaint early this year alleging that she was sexually assaulted by Michael Corn, who was then her boss as the top producer of “Good Morning America.”

Kirstyn Crawford, a producer on the show, filed suit last month against Mr. Corn and the network. In an amended version of the suit filed Wednesday, she alleged that after she formally registered her complaint at ABC the network didn’t renew her three-year contract, offering instead a six-month...

An ABC News staffer claimed the network retaliated against her after she filed a complaint early this year alleging that she was sexually assaulted by Michael Corn, who was then her boss as the top producer of “Good Morning America.”

Kirstyn Crawford, a producer on the show, filed suit last month against Mr. Corn and the network. In an amended version of the suit filed Wednesday, she alleged that after she formally registered her complaint at ABC the network didn’t renew her three-year contract, offering instead a six-month extension with no raise.

In her suit, Ms. Crawford alleged that Mr. Corn sexually assaulted her during a 2015 reporting trip to Los Angeles. The suit also alleges that former ABC News producer Jill McClain was sexually assaulted by Mr. Corn when the two worked together roughly a decade ago. Ms. McClain, who left ABC in 2013, isn’t a plaintiff in the suit but is supporting Ms. Crawford’s case, according to the complaint.

Mr. Corn, who left ABC News in April, has denied wrongdoing and said in a statement that the allegations made by Ms. Crawford and Ms. McClain are fabrications.

A spokesman for ABC News didn’t immediately respond to a request for comment on the allegation that the network retaliated against Ms. Crawford.

The suit also alleged that ABC failed to act on complaints it had received about Mr. Corn’s conduct from several women over roughly a decade. ABC News said last month that it “disputes the claims made against it and will address this matter in court.”

According to the amended lawsuit, Ms. Crawford’s formal complaint to ABC in February came six months before the end of her three-year contract as a producer for “Good Morning America” anchor George Stephanopoulos.

According to the suit, the network typically approaches employees a few months before a contract expires to renegotiate a new contract. In this instance, ABC News didn’t contact Ms. Crawford until July, just weeks before her deal expired, the suit said. Ms. Crawford is still working at ABC News, without a contract.

Although Ms. Crawford didn’t make a formal complaint at ABC until earlier this year, the network learned of her alleged encounter with Mr. Corn in 2017 and failed to investigate the matter, according to the suit. The suit said Mr. Stephanopoulos was told by a third party about the alleged incident and informed ABC management. Mr. Stephanopoulos has said the suit’s depiction of his actions is accurate.

After Ms. Crawford and Ms. McClain made their complaints to ABC, the network conducted an investigation and Mr. Corn was pushed out, according to people familiar with the matter. ABC also held unsuccessful mediation talks with the two women in June, The Wall Street Journal reported.

Write to Joe Flint at joe.flint@wsj.com