* U.S. sends choppers, troops to support relief efforts
* Deaths from two typhoons at over 600
* Damage to crops and infrastructure estimated at $324 mln
(Updates death toll, adds comments from economic adviser)
MANILA, Oct 11 The Philippines turned its focus on Sunday from rescue operations to sending relief to northern provinces devastated by floods and cut off by landslides as the death toll from two typhoons in 14 days rose to more than 600.
Using shovels and their bare hands to avoid triggering more landslides, rescue teams kept up a search for bodies in the areas of northern Luzon island that remained isolated.
But Defence Secretary Gilberto Teodoro said in a television interview: "The most important thing is to open roads so we can send relief goods because we cannot hope to find alternate routes.
"We have a massive push using our assets -- the armed forces, coast guard, police, and the U.S. forces are in the north."
Officials considered a possible $1 billion rehabilitation plan for typhoon-hit areas to be funded mostly by foreign aid.
U.S. troops on exercises nearby sent a C130 transport plane and three Chinook helicopters to help bring food and medicine to Baguio City in mountainous Benguet province, 250 km (155 miles) north of the capital, and nearby areas cut off by landslides.
"As of now, food and relief materials can only be delivered by helicopters because it will take two to five days to clear up roads and bridges washed out by floods and landslides," said Lieutenant-Colonel Ernesto Torres, spokesman for the national disaster agency.
Lieutenant-Colonel Romeo Brawner, spokesman for the Philippine military, said: "We are now slowly diverting our attention from rescue operations to disaster relief operations."
BOULDERS BLOCKING ROADS
Olive Luces, head of the civil defence office in the northern Cordillera region, said the main access roads to Baguio City were still cut off by landslides.
He said boulders twice as high as commuter vans blocked the winding highway snaking through the mountains.
The latest report from the national disaster agency put the death toll from Typhoon Parma, which hit the Philippines a week ago, at 193, including 134 from Benguet province alone.
But Luces said at least 152 died in Benguet, a toll higher than in the official report, with 50 others killed in Baguio and 29 in the nearby Mt. Province not included in the report by the national headquarters.
Initial estimates of damage from the two storms on production of rice, the country's staple, was estimated at 478,000 tonnes, equivalent to 7 percent of the forecast harvest of 6.5 million tonnes in the fourth quarter, Jesus Emmanuel Paras, agriculture undersecretary, said on Saturday.
Manila, the world's biggest rice buyer, is considering importing rice to augment its supply for 2010 after the typhoon damage, with Vietnam and Thailand eager to provide the grain. [ID:nSP270827]
Teodoro said total damage to crops and infrastructure from the two storms amounted to at least 15 billion pesos ($324 million), with the Philippines now rushing a 10 billion peso additional budget for 2009 to fund rehabilitation efforts.
Joey Salceda, governor of Albay province in central Philippines and the president's economic adviser, proposed creating a $1 billion fund, overseen by a committee made up of members of the public and private organisations, to rebuild areas devastated by the typhoons.
Salceda said the government should tap foreign donor agencies and bilateral partners to commit funds in an international pledging session that could be held in Spain and Japan, the top two providers of bilateral grants to the country.
Besides setting off landslides in the mountains, rains dumped by Typhoon Parma have swollen rivers and reservoirs, forcing dams used for hydropower and irrigation to release water and causing more flooding in areas downstream.
Parma first hit the Philippines on Oct. 3 and hovered around the northern part of the main Luzon island throughout the week before weakening and moving out to sea.
The floods and mudslides came two weeks after another storm, Ketsana, inundated areas in and around Manila, killing 337 people and forcing half a million from their homes. (Reporting by Manny Mogato and Rosemarie Francisco, Editing by Jeffrey Heller)