Bulgaria's defence ministry said on Monday that it has signed a 17 million levs ($10 million/8.7 million euro) seven-year framework agreement with a local company, Yotov and Son Bulgaria, on ensuring the airworthiness of the country's eight L-39ZA trainer aircraft. Yotov and Son Bulgaria intends to delegate 85% of the activities on the overhaul of the aircraft to a subcontractor - Ukraine's State Enterprise Odessa Aircraft Plant, according to a notice published by the defence ministry. Yotov and Son Bulgaria filed the only offer in a public procurement procedure for the contract. The Aero L-39 Albatros is a high-performance jet trainer developed by Czech aircraft manufacturer Aero Vodochody. According to commercial register data, Yotov and Son Bulgaria is owned by private investors Ivaylo Yotov and Nayaliya Yotova.It posted a net profit of 26.8 million levs on 70.7 million levs turnover in 2016, according to latest available financial data in the commercial register. It was set up in 1991, according to data published on its website.