ST PETERSBURG - Qatar Airways plans to seek compensation from Boeing over the grounding of three 737 MAX aircraft by Italian airline Air Italy, where the Qatari company is a major shareholder, group chief executive Akbar al-Baker told Reuters.

Boeing MAX jets have been grounded worldwide and airlines are cancelling multimillion contracts following crashes in October and March that killed nearly 350 people.

"At Qatar Airways we do not operate any MAX airplanes – it affected our investment into Air Italy. Air Italy has three MAX operated in its fleet and they were grounded so it affected us – we had to take extra routing from outside," al-Baker said.

In 2017, Qatar purchased 49% of Air Italy, Italy's second largest carrier behind Alitalia, which, in turn, is partly owned by Abu Dhabi’s Etihad Airways.

"Boeing has to compensate us for grounding," al-Baker said, but did not elaborate on the potential cost.

In Russia, Qatar Airways is in talks to buy a 20% stake in Vnukovo airport, Moscow's third largest by passenger traffic.

Al-Baker said Qatar Airways was looking to close the deal "sometime before the end of the year."

Last year, Vnukovo's handled around 21 million passengers, compared with 29 million at Domodedovo and almost 46 million at Sheremetyevo, Russia's biggest airport and one of the busiest in Europe.

"Sheremetyevo and Domodedovo are already congested and the only airport that has an expansion opportunity is Vnukovo," Al-Baker said.

"We see a huge potential to grow the airport to bring more traffic, to intensify traffic, to grow there, to increase the duty free footprint."

Asked if Qatar Airways could consider acquiring a stake in Sheremetyevo, 30% of which may be on offer by the airport's private shareholders, Al-Baker said: "We cannot do more than one airport at the same place."

At home, at Hamad International Airport in Doha, passenger traffic was at around 35 million people last year.

"This year we hope that we will exceed 42 million passengers but during the blockade we did lose nearly 10% of the traffic because it was all of a sudden. But we have recovered now," Al-Baker said.

Saudi Arabia, the United Arab Emirates, Bahrain and Egypt imposed an economic and diplomatic boycott on Qatar in 2017 over allegations that Qatar supports terrorism and is aligning itself with regional foe Iran. Qatar denies the allegations.

(Reporting by Katya Golubkova; Additional reporting by Gleb Stolyarov; Editing by Andrey Kuzmin and Mark Potter) ((ekaterina.golubkova@thomsonreuters.com; +7 495 775 1242;))