Lufthansa Technik Sofia has signed a 10-year contract with Russian operator Air Tatarstan to provide heavy maintenance for its fleet of Airbus A319 and Boeing 737 Classic aircraft.

The maintenance agreement will cover light C check and heavy D check maintenance visits at Lufthansa Technik’s hangar in Sofia, Bulgaria.

The agreement will include maintenance for Air Tatarstan’s one A319 and five 737 Classics. Lufthansa Technik says the agreement will cover the purchase of any additional aircraft within the 10-year contract period.