Warren Buffett said that Berkshire’s increased stake in Delta Airlines mistakenly breached his comfort threshold of 10% due to buybacks by Delta. This according to an article in Bloomberg.

The article reports that in an interview with CNBC, Buffett said, “What I didn’t realize was that that purchase had taken us over 10 percent. I was already in territory I didn’t plan to get, so I just decided to buy a whole lot more stock.” After swearing off the airline industry for years (in the wake of a losing stake in US Airways in 1989), Buffett has changed his tune on the industry since 2016, beefing up his stakes in Delta, Southwest, American and United. This has fueled speculation that his ongoing search for a mega-deal (and a channel for Berkshire’s hefty cash balances) might lead to an outright purchase of a carrier.

The article cites Buffett’s comment that while the airline business is “very, very competitive, “I don’t think it’s a suicidal business anymore, but it was for a while.”