The Bulgarian capital's local government said a total of 11 companies and consortia filed bids in a tender for the design and construction of a municipal waste recycling plant.
The winner will be named in October, as the project is due to be completed in 21 months, the municipality said in a statement on its website.
The estimated value of the contract is 208.3 million levs ($141.4 million/106.5 million euro), inclusive of Value Added Tax.
Back in 2010 Sofia picked German-Bulgarian tie-in HUT-Stanilov to build the plant. However, the procedure was cancelled due to changes in the project's technical specifications requested by the European Commission.
The eligibility requirements in the current procedure include a combined turnover of at least 250 million levs for 2008, 2009 and 2010 and prior expertise in the construction and commissioning of at least one mechanical-biological treatment system with a capacity of over 200,000 tonnes per year.
Sofia's 2.0 million residents produce some 390,000 tonnes of waste annually.