Norwegian Air has agreed to buy 50 Boeing 737 MAX 8 aircraft and secured options for a further 30 of the planes at an undisclosed price, the budget carrier said on Monday.

The deal is a boost for Boeing, anchoring long-standing customer Norwegian to the U.S. plane maker after the Oslo-based airline earlier this year said it would consider switching to rival Airbus.

For Norwegian the deal marks a return to aircraft ownership after it was forced to resort to leasing deals during bankruptcy proceedings that rescued the company last year.

"The 50 aircraft are due to be delivered between 2025 and 2028, at a schedule closely corresponding to current aircraft lease expirations. This entails a limited net increase of the company's current fleet," Norwegian said in a statement.

As a result of the agreements, the airline said it expects to book a net gain of approximately 2 billion crowns ($212.2 million) after concluding the deal, boosting its equity. It did not elaborate.

"This is a landmark deal that sets out a path whereby Norwegian will own a large share of its fleet," board Chair Svein Harald Oeygard said.

"This will result in lower all-in costs and increased financial robustness, enabling us to further solidify our Nordic stronghold."

Norwegian in February told Reuters it was considering a switch to Airbus unless ongoing litigation with Boeing over previous aircraft cancellations was resolved in a timely fashion.

Norwegian's aim is to bring an end to the legal dispute with the U.S. plane maker before a final closing of the new aircraft deal is signed, likely by the end of June, a source with close knowledge of the transaction said.

It was Boeing's second major European order in recent weeks for MAX aircraft following a deal with airlines giant IAG .

($1 = 9.4243 Norwegian crowns)

(Reporting by Terje Solsvik, editing by Gwladys Fouche and Susan Fenton)