SOFIA (Reuters) - Bulgaria has asked Russian Aircraft Corporation MiG to overhaul and maintain its 15 aged MiG-29 fighter jets in a four-year deal worth up to 81.3 million levs ($49 million), the country’s defense ministry said on Monday.

NATO and EU member Bulgaria needs to keep its Soviet-era aircraft operational after plans to buy eight new fighter jets hit another snag.

The defense ministry will have to virtually restart the process and is yet to send requests for proposals to aircraft makers.

Main contenders remain Swedish manufacturer Saab’s Gripen jets, Portugal and the United States with secondhand F-16s and Italy with secondhand Eurofighter Typhoons. Defence Minister Krasimir Karakachanov has said Bulgaria may also send a request to Boeing for F-18 aircraft.

($1 = 1.6586 leva)