NEW YORK — “Today” show host Matt Lauer was fired for what NBC on Wednesday called “inappropriate sexual behavior” with a colleague and was promptly confronted with a published report accusing him of crude and habitual misconduct with other women around the office.

With his easygoing charm, Lauer has long been a lucrative and highly visible part of NBC News and one of the highest-paid figures in the industry, and his downfall shook the network and stunned many of the roughly 4 million viewers who start their day with him.

He is easily one of the biggest names brought down in recent weeks by the wave of sexual misconduct allegations that have swept through Hollywood, the media and politics.

Network news chief Andrew Lack said in a memo to the staff that NBC received a complaint about Lauer’s behavior on Monday and determined he violated company standards. NBC said the misconduct started when Lauer and a network employee were at the Sochi Olympics in 2014 and continued beyond that assignment.

Lack said it was the first complaint lodged against Lauer in his 20 years at NBC, but “we were also presented with reason to believe this may not have been an isolated incident.”