Bulgaria's defence ministry said on Wednesday that it has signed a 42.2 million euro ($48.4 million) deal with Belarus' Aircraft Repair Plant 558 for ensuring the airworthiness of eight Su-25 fighter-bombers and 16 R-95Sh jet engines. This is the first contact under a four-year framework agreement signed between the two parties last year, the ministry said in a notice. The deal significantly exceeds the initial estimated value of the framework agreement, of 41 million levs ($23.9 million/21 million euro). Last year, the defence ministry invited 558 Aircraft Repair Plant and Russia's United Aircraft Corporation to run in the tender. However, United Aircraft Corporation did not submit an offer. The overhaul of the Su-25 ground attack aircraft is already 10 years overdue, the ministry said at the time.