Anglo-Irish oil company Aminex has signed a 20-year deal to develop North Korea's oil industry.
North Korea's countryside may be hiding oil and gas deposits
Aminex said it would provide technical assistance to North Korea. In addition, it will be permitted to explore and drill throughout the secretive country.
Should Aminex strike oil, it will get royalties on any of its own production, as well as being entitled to earnings from wells drilled by other firms.
Aminex believes its prospects of striking oil in North Korea are good.
"We all dream of making a big discovery," chief executive Brian Hall told BBC News Online. "And if you don't put yourself in a position where the possibilities are high, you will never do it."
A number of potential sites are close to some of China's most productive oil fields, he said. Announcing the contract, Aminex called North Korea as "highly prospective".
The company, which is listed on the London and Dublin stock markets, reckons that a lack of resources has so far restricted progress in prospecting for oil the East Asian country.
North Korea "has an existing petroleum industry and several wells have been drilled onshore and offshore over a 25 year period, resulting in limited discoveries of oil," Mr Hall.
Aminex has been looking at opportunities in North Korea since its first visit there in 2001.
It signed a deal with North Korean officials on 30 June 2004 in Pyongyang but postponed an announcement "because of a number of outstanding issues that have now been resolved".
Mr Hall said he hoped that developing the oil industry might help to thaw international relations, which have become frosty in recent months amid concerns about the country's nuclear programme.
"At present, relations between North Korea and the outside world are strained but the important relationship with South Korea appears to be improving and commercial co-operation is on the increase," said Mr Hall.
"An expanding energy industry may possibly help to build bridges between North Korea and the outside world."
North Korea is one of the world's most secretive countries, and among the poorest.
Millions of are thought to have died during the famine of the late 1990s. More recently, North Korean officials have made tentative steps towards economic reforms similar to those implemented by China, one of its few allies. But tensions over the country's nuclear programme remain a stumbling block to investment.
Aminex has existing operations in the US, Russia and Tanzania.