Steve Wynn, the billionaire casino visionary considered to be the architect of modern Las Vegas, resigned Tuesday as chairman and chief executive of his company in the wake of sexual misconduct allegations detailed in a Wall Street Journal investigation last month.

Mr. Wynn, 76 years old, who founded Wynn Resorts Ltd. in 2002, said in a statement Tuesday evening he “reached the conclusion I cannot continue to be effective in my current roles” after becoming the focus of “an avalanche of negative publicity.”

Matt Maddox, currently the company’s president, will take over as CEO, according to a statement from the company.

A spokesman for Wynn Resorts said the company had no comment beyond its statement announcing Mr. Wynn’s resignation.

On Wednesday, Mr. Wynn also resigned as chairman and CEO of Wynn Macau Ltd. He has been replaced by Mr. Maddox as CEO, while Hong Kong-based businessman Allan Zeman is the new non-executive chairman.