Retired US army General Wesley Clark, who led the NATO campaign to drive Serbian forces out of Kosovo 13 years ago, is now hoping to dig deep to tap the territory\'s coal resources. His company Envidity, which focuses on clean energy, has applied for a licence to explore in Kosovo and produce synthetic fuel if significant coal deposits can be found. The Canadian company, of which Clark is chairman, said if the exploration was successful it could eventually produce up to 15.9 million litres (100,000 barrels) a day of high-quality synthetic diesel fuel. Endivity estimates the Pristina government could benefit to the tune of 300 million euros, which it said was one fifth of its current revenue. Kosovo\'s known lignite or brown coal reserves are estimated at up to 14 billion tonnes. A spokesman for the ministry for economic development, Gezim Baxhaku, said the application was being reviewed. Clark led the NATO air war that ousted Serbian forces loyal to then strongman Slobodan Milosevic who fought against independence-seeking ethnic Albanian guerrillas in the 1998-1999 conflict. Kosovo declared independence in 2008, a move recognised by some 90 countries including the US and a majority of EU members but not Serbia.