Budget airline Ryanair says its profit fell 29% last year and warns that the grounding of Boeing's 737 Max planes will limit its ability to cut costs.

Europe's largest carrier by passengers said earnings for the year ending March 31 fell to 1.02 billion euros ($1.14 billion) from 1.45 billion euros the previous year. Strong 7% traffic growth was offset by a 6% decline in fares.

Boeing grounded its 737 MAX planes after two crashes raised concerns about flight-control software. It said last week it has finished updating the software, though it remains unclear when the grounding will end.

Ryanair had wanted to use the fuel-efficient planes to cut costs. But it delayed delivery of its first five Max planes until the winter so those savings won't happen until 2021.