* Peace talks in Norway end with timeframe to continue
* Social and political reforms at heart of dispute
* Conflict has lasted 25 years
(Updates with new quotes, details, previous MANILA)
By Walter Gibbs and Manny Mogato
NESBRU, Norway/MANILA, Philippines, Feb 21 (Reuters) - The Philippine government and communist guerrillas whose conflict has taken 40,000 lives and stunted economic growth for five decades agreed on Monday to an 18-month timetable of formal peace talks.
"We have moved the peace negotiations forward, ending a six-year impasse," said Luis G. Jalandoni, chief negotiator of the National Democratic Front (NDF), whose demands include land reform to benefit landless Filipinos.
Among the forces Jalandoni represents is the Communist Party's New People's Army, whose more than 4,000 fighters are known for attacking political leaders and businesses such as mining operations, according to the International Crisis Group.
Negotiations between the government and rebels have been held on-again-off-again for some 25 years, with Norway bringing the adversaries together several times over the past decade.
Each side sent about 25 people to Norway but few analysts expected a breakthrough. [ID:nLDE71E0FN]
Closed-door talks to revive contact between the adversaries and discuss social and political reforms ended late on Monday at a hotel outside the Norwegian capital.
"We have agreed on a timeframe of 18 months to produce substantive agreements on socio-economic reforms, on political and constitutional reforms and on the end of hostilities and disposition of forces leading to a final political settlement," Alexander Padilla, chairman of the Philippine government's delegation, said.
Norwegian facilitator Ture Llundh said setting a timetable with milestones was progress in itself. "We did not expect any better than this," he said.
In the Philippines, the political content of the Norwegian meeting was eclipsed by the arrest of a top communist leader on Feb. 14 and accusations that both sides have violated a ceasefire put in place for the talks.
The conflict is one of two long-running insurgencies that have hobbled development and investment in the Southeast Asian nation.
The government's attempts to suppress the Moro Islamic Liberation Front, or MILF, in southern Mindanao tends to get more international attention than the simmering conflict with Maoists active in 69 of 80 Philippine provinces.
The NDF says on its website that it is fighting against a "semi-colonial and semi-feudal" Phillipine state dominated by the United States.
Jorge Madlos, known as Ka (comrade) Oris, NDF spokesman on southern island Mindanao, said soldiers had violated the ceasefire by going on patrols and attacking rebel positions in the mining province of Compostela.
"These violations are indelible marks of the government's hypocritical and disingenuous attitude towards the peace process," Madlos said in a media statement.
Army commander Lieutenant-General Arturo Ortiz said it was the rebels who violated the ceasefire, saying soldiers had stopped Maoist New People's Army guerrillas from laying landmines on the central island of Samar on Saturday.
(Reporting by Manny Mogato in Manil and Walter Gibbs in Nesbru, Norway; editing by Michael Roddy)