"For the past twenty years, he has figured prominently in endeavours to resolve several serious and long-lasting conflicts," the committee said in announcing the 10 million kronor (US$1.4 million) prize.
Ahtisaari, 71, selected out of a field of 197 candidates, said he hoped the Nobel Peace Prize would make it easier to attract financing for his peace work, according to a report from AP.
"There are always many possibilities. I really hope now that I receive the prize that it makes it easier to finance the organizations that I chair," he said. "It's very important to be able to act properly, you need financing and you never have enough."
Ahtisaari was a senior Finnish diplomat and in 1977 he was named the U.N. envoy for Namibia, where guerrillas were battling South African apartheid rule. He later rose to undersecretary-general, and in 1988 was dispatched to Namibia to lead 8,000 U.N. peacekeepers during its transition to independence. He played a significant part in the establishment of Namibia's independence.
In 2005, Ahtisaari also founded the Crisis Management Initiative (CMI), an independent, non-governmental group for developing and sustaining peace. It was central to the solution of the complicated Aceh question in Indonesia.