Facebook owner Meta will lay off more than 11,000 of its staff in "the most difficult changes we've made in Meta's history", boss Mark Zuckerberg said on Wednesday.

He said the cuts represented 13 percent of the social media titan's workforce and would affect its research lab focusing on the metaverse as well as its apps, which include Facebook, Instagram, and Whatsapp.

The tech industry is in a serious slump and several major firms have announced mass layoffs — Twitter's new owner Elon Musk fired half its staff last week.

"I want to take accountability for these decisions and for how we got here," Zuckerberg said in a note to staff.

"I know this is tough for everyone, and I'm especially sorry for those impacted."

Ad-supported platforms such as Facebook and Google are suffering with advertisers looking to cut costs as they struggle with inflation and rising interest rates.

Zuckerberg told staff he had expected the boost in e-commerce and online activity during the Covid pandemic to continue but added: "I got this wrong, and I take responsibility for that."

Metaverse woes 

The downturn has affected companies across the sector, with Apple and Amazon also recently announcing results that disappointed investors.

But Meta also faces some unique problems of its own.

Investors have been worried about Zuckerberg's decision to devote billions of dollars to developing the metaverse, an immersive version of the web accessed via virtual reality headsets.

Zuckerberg renamed the company to Meta a year ago to reflect the commitment to the project, but the division working on metaverse technology has since made losses of more than $3.5 billion.

He has hinted several times this year that belt-tightening measures were just around the corner and said in his letter on Wednesday that staff layoffs were a "last resort".

Meta would also keep a hiring freeze going into next year, he said, and other spending cuts were envisaged.

"Fundamentally, we're making all these changes for two reasons: our revenue outlook is lower than we expected at the beginning of this year, and we want to make sure we're operating efficiently," he wrote.

Last month, Meta announced profits of $4.4 billion in the third quarter, a 52 percent decrease year-on-year, causing its stock price to fall 25 percent.

The slump in profits comes despite its platforms dominating the world in terms of users — Facebook alone claims to have around two billion people who log on daily.