Sofia's municipality picked Greek tie-up Aktor-Helektor to build a waste-to-biofuel plant with an annual capacity of 410,000 tonnes of waste.
The Greek tie-up offered to carry out the works for 213.5 million levs ($142.8 million/109.2 million euro), compared with a 204.8-million levs offer from the other bidder - consortium Sardinata 2012, the Sofia municipality said in a statement.
The Aktor-Helektor bid received an overall score of 181.53 points with a price of 60.69 levs per tonne of processed waste, while Sardinata 2012 got 149.23 points with a price of 72.43 levs per tonne.
The other three bidders were disqualified as their bids did not meet the tender requirements.
The plant's construction has to be completed within 19 months upon signing the contract.
This is the second stage of the project for construction of an integrated waste management system in the Bulgarian capital city.
The plant will treat more than three quarters of the city's waste and will produce energy from refuse-derived fuel, which will be used for heating production by the city's heating utility Toplofikatsiya Sofia, reducing its usage of natural gas by at least 10%.
The combined value of the two stages in building Sofia's waste management system is 346 million levs, from which as many as 84.26% are extended as a grant by the EU.