Bulgaria's Defense Ministry has signed a deal to acquire 10 MiG-29 engines from Russia, officials say.

The contract was signed with a Russian company which will deliver the first two repaired engines by April 30, 2017. Two engines are to be delivered to Bulgaria every month afterwards until all have been received.

The Defense Ministry argues that the new contract, dated November 09, will allow to make five more MiGs flyworthy next year.

In October, a tender launched for the procurement of the engines was scrapped as a single bidder had appeared, allegedly demanding higher-than-normal prices.

However, Bulgarian Prime Minister Boyko Borisov told private bTV station on Wednesday that the contract, sealed with an unnamed Russian company, had a price tag of BGN 42 M, considerably higher than the BGN 30 M envisaged in the tender stage.

Capital daily cites its own sources who say the engines will be supplied by Aviostart, the Bulgarian company that took part in the tender, but will be purchased by RSK MIG, the original equipment manufacturer.

Initially, Defense Minister Nikolay Nenchev had insisted Bulgaria will go for Russian-made ones, but these would not be supplied by Russia.

Last year, Bulgaria also signed with Poland a deal to overhaul six MiG-29 engines of aircraft that are in service with the Bulgarian Air Force.

The MiG-s' flying capacity has to be urgently extended as the approved procurement of sixteen new or repaired aircraft by the end of the year will only result in Bulgaria using the jets in 2020. It will need to extent the MiGs' flying capacity to conduct joint air-policing missions with NATO partners by the time.

The aircraft deal is not expected to be finalized before the end of the year.