- European Bank for Reconstruction and Development (EBRD)
- European Investment Bank (EIB)
- International Financial Corporation (IFC)
- World Bank (WB)
- Council of Europe Development Bank (CEB)
- Atkins (UK)
- Arup (UK)
- D’Appolonia (Italy)
- WSP Environment and Energy (UK)
- Mott MacDonald (UK)
- Citrus Partners LLP (UK)
- SCE (France)
- Rakita d.o.o. (Serbia)
- Freeport Macmoran Exploration Corporation (USA)
- EFT Group (Serbia)
- POVVIK AD (Bulgaria)
- Enova (Bosnia and Herzegovina)
- Ceteor (Bosnia and Herzegovina)
- Green Cell Consulting d.o.o. (Serbia)
- Bankers Petroleum (Canada)
- RePlan (Canada)
- Dekonta (Czech Republic)
- Bishkek City (Kyrgyzstan)
- Ivicom Holding (Austria)
- Barki Tojik (Tajikistan)
- KfW IPEX
- Rio Sava Exploration (Serbia)
