DAVOS -- Aimed at helping the ex-Soviet nation ease its dependence on Russia, Ukraine and the global oil giant Royal Dutch Shell (IW 1000/1) signed Thursday a $10 billion shale gas production sharing agreement.

The deal was signed in the presence of Ukrainian President Viktor Yanukovych by Shell CEO Peter Voser and Ukrainian Energy Minister Eduard Stavitsky on the sidelines of the World Economic Forum in Davos, a gathering of the world's business and political elite.

Earlier Thursday, Stavitsky put the value of the deal at $10 billion.

Yanukovych said the deal was "only the beginning" and vowed: "From now on we will also be able to find a flexible method of co-operation that will add value to both our countries' economies."

Voser said it was a "very important day for Shell" and acknowledged it was a "big step" for his firm.

The Ukrainian government estimates the eastern Donetsk location may hold three trillion cubic metres (100 trillion cubic feet) of natural gas -- enough to last the nation of 46 million people 70 years at current consumption rates.

Shell will sink 15 exploratory wells in the Yuzovska field in an area of 7,000 3,000 square miles, according to Ukraine's Natural Resources Minister Oleh Proskuryakov, cited in the Kommersant daily.

The Shell deal comes amid an upsurge of foreign interest in Ukrainian shale gas -- tapped by a controversial process known as fracking -- after the industry took off in North America.

Some forecasts suggest that Ukraine alongside countries such as France and Poland may hold some of Europe's largest shale rock deposits.