NEW YORK —  NBC has fired lead morning news anchor Matt Lauer over sexual harassment allegations, the network’s president for news said in a memo to staff on Wednesday.

"Matt Lauer has been terminated from NBC News. On Monday night, we received a detailed complaint from a colleague about inappropriate sexual behavior in the workplace by Matt Lauer. As a result, we’ve decided to terminate his employment," the Today Show tweeted Wednesday morning. 

NBC News Chairman Andrew Lack said the network had received a complaint from a colleague on Monday night, and a review determined it was a clear violation of company standards. While it was the first complaint lodged against Lauer, Lack said in a memo to staff that "we were also presented with reason to believe this may not have been an isolated incident."

Lauer, 59, has hosted "Today" for two decades. When paired with Katie Couric, "Today" was the longtime ratings leader and was highly lucrative for NBC. It now runs second in the ratings to ABC's "Good Morning America."

Many "Today" show viewers took out their anger for the unsightly 2012 firing of co-host Ann Curry on Lauer, sending the show plunging in the ratings. But NBC stuck with Lauer and the show had steadied with his pairing with Samantha Guthrie. The show runs for four hours, with Lauer and Guthrie hosting the first two.

Associated Press contributed to this report.