Bulgaria's defence ministry said on Thursday that it has opened a tender for two framework agreements, envisaging the repair of 13 T-72 Russian-made battle tanks and the repair of 60 rangefinders for the tanks, respectively. The contract for repair of the tanks has an estimated value of 6.67 million levs ($4 million/3.4 million euro), while the other contract is valued at 1.5 million levs, the defence ministry said in a tender notice. The tank-repair contract envisages repair of two tanks in 2018, four each in 2019 and 2020, and three in 2021. The rangefinders should be repaired in batches of 12 over a five-year period. Earlier this week, Bulgaria invited Russia's United Aircraft Corporation (UAC) and Belarus' 558 Aircraft Repair Plant (ARP) to submit offers for a contract for ensuring the airworthiness of the country's Su-25 fighter-bombers. The estimated value of the contract is 41 million levs.