Social-networking Web site MySpace yesterday said it will lay off more than 400 employees in an effort to cut costs and boost profitability.

MySpace, which like The Post is owned by News Corp., said it would reduce its staff across all US divisions by near 30 percent, or about 420 people. That will leave the operation with about 1,000 US-based employees.

“Simply put, our staffing levels were bloated and hindered our ability to be an efficient and nimble team-oriented company,” said new MySpace CEO Owen Van Natta in a statement.

News of the job cuts came in the same day that new data showed that rival social-networking site Facebook pulled in 70.28 million users in May, while MySpace recorded 70.26 million, according to new figures from Web traffic tracking service comScore. It was the first time that Facebook beat MySpace in that metric.

MySpace claims that the restructuring is aimed at returning the company to a start-up culture.

But a more accurate explanation would be that the Web site is trying to bring costs in line with revenue, which is expected to take a severe hit once Google’s $900 million ad-revenue sharing pact expires next year.