Facebook said on Friday its accounting chief is leaving the company and that it will undertake its first-ever stock buyback program, worth $6 billion.

Chief Accounting Officer Jas Athwal — a nine-year veteran of Facebook, who was promoted to his current role in 2013 — is “retiring,” a source close to the company said, adding that Facebook has begun an external search to find a replacement.

Asked Friday about Athwal’s age, Facebook officials declined to comment. His Wikipedia page has him at 53.

The share-buyback program, slated to begin in the first quarter, comes as Facebook’s stock has taken a beating lately.

The shares are off 10 percent after the company warned earlier this month that its profit growth will slow “meaningfully” next year as the space for ads on its social network tightens.

Meanwhile, Chief Executive Mark Zuckerberg has been slammed by critics over a barrage of fake news that hit users’ screens during the presidential campaign, with some claiming that it may have tipped the outcome.

Earlier this week, Facebook admitted it has been overestimating the performance of its ads, according to several metrics — the second such admission this year.

Athwal has recently been selling Facebook shares, including two trades in August worth $2.5 million at prices around $124 a share, according to securities filings.

Facebook shares lost 77 cents Friday, to close at $117.02.