Oculus co-founder Brendan Iribe leaves Facebook

A co-founder of Facebook's virtual-reality division is joining the exodus of executives to leave the company after striking it rich in lucrative sales of their startups.

Oculus co-founder Brendan Iribe disclosed his decision to leave Facebook in Monday tweet, as well as a post on his Facebook page. His departure comes 2 1/2 years after Facebook parted ways with Oculus' other co-founder, Palmer Luckey.

Both Iribe and Luckey joined Facebook in 2014 after selling Oculus to the company for $2 billion. Iribe had been Oculus' CEO until 2016 when he shifted to a lower-ranking job in the virtual reality division.

Facebook issued a statement Monday hailing Iribe for pushing virtual reality "far beyond the boundaries of what people thought possible and it's because of his vision that we're all here working on VR today. We're thankful for his leadership, his dedication to building the impossible, and he'll be missed."

Oculus is considered a pioneer in making the virtual reality headsets that immerse users in artificial, three-dimensional worlds. Despite Facebook's backing, virtual reality remains a niche field of technology popular primarily among video game fans looking for even more compelling entertainment.

Facebook CEO Mark Zuckerberg is hoping to expand virtual reality's appeal with next year's release of the Oculus Quest headset.

It's not unusual for startup founders such as Iribe to leave much larger companies several years after selling to them.

But Facebook has been hit with a wave of departures over the past six months, raising questions whether Zuckerberg's push for new areas of revenue growth beyond the company's social networking service is raising tensions in the executive ranks.

In April, WhatsApp CEO Jan Koum left Facebook four years after selling the messaging app, and last month Instagram CEO Kevin Systrom and fellow co-founder Mike Krieger bolted . Facebook bought Instagram for $1 billion in 2012.

Iribe thanked Zuckerberg for his support of Oculus in his parting note on Facebook. "We started a revolution that will change the world in ways we can't even envision," Iribe wrote.

But Systrom hinted there might have been some discord brewing in Facebook during an appearance last week.

"No one every leaves a job because things were awesome," he said.