The chief of budget airline Ryanair said Monday he fully expects some of his European rivals to file for bankruptcy over the coming months.

The Irish airline warned that elevated oil prices — and consequently fuel costs — would probably cause some of its regional peers to go bust in early 2019. A dramatic upswing in crude futures over the past 12 months has weighed on the industry, at a time when major airlines are being forced to adapt to a much more competitive marketplace.

"Clearly $80 a barrel oil is going to bring casualties in Europe this winter," Ryanair CEO Michael O'Leary told CNBC's "Squawk Box Europe" Monday.

"Oil is going to be a driver but I think it will be a driver of change to the competition landscape in Europe. Some of those airlines who couldn't make money when oil was at $40 a barrel last year, I don't think will survive this winter if oil remains up at these elevated levels," he added.

Brent crude futures traded near multi-year highs at $79.16 a barrel on Monday morning, up 0.8 percent, while WTI stood at $71.81 a barrel, 0.7 percent higher.