SAN FRANCISCO — Uber said it laid off a third of its marketing team on Monday, or about 400 people, as the ride-hailing company tries to cut costs and streamline its operations after its initial public offering in May.

The cuts, which were also announced internally on Monday, are taking place in multiple Uber offices around the world, the company said. The marketing team had more than 1,200 people before the layoffs. Uber employs almost 25,000 people globally, nearly half of whom are based in the United States, according to recent regulatory filings.

Uber declined to comment further.

The layoffs are the latest shake-up at Uber since it went public two months ago. During its journey to the public markets, the company, which is unprofitable, faced numerous questions from Wall Street about whether it could make money. Ride-hailing is an expensive business, with providers often spending huge sums to recruit drivers and subsidize trips. Those doubts ultimately took a toll on Uber’s I.P.O., with the company’s stock falling 7.6 percent on its first day of trading on the New York Stock Exchange.

Since then, Dara Khosrowshahi, Uber’s chief executive, has moved to make changes at the company. In June, he pushed out two members of his executive team: Barney Harford, the chief operating officer, and Rebecca Messina, the chief marketing officer. Ms. Messina’s role was eliminated, and the marketing team was reorganized under Uber’s communications lead, Jill Hazelbaker.