China's southwestern Tibet Autonomous Region is to postpone the completion of the region's three key cultural relics renovation, which is scheduled to be finished in June 2007, till the end of next year, sources from Tibet local bureau of cultural relics protection.

Project to repair three key cultural relics in Tibet includes the Potala Palace, Norbu Lingka and Sagya Monastery. Started from June 26, 2002, expenditure on the project is allocated by the State Council, which is estimated at some 330 million yuan, reserving the most important projects in Tibet.

With six years' effort, 150 sub projects out of 156 totalling, worth about 280 million yuan, over 80 per cent of the total budget, have by far been completed.

Among the total investment, 150.92 million yuan went for the Potala Palace, 62.64 million yuan was invested for the Norbu Lingka while the rest was pumped into renovation project at the Sagya Monastery.

So far, maintenances of the Potala Palace and Norbu Lingka have basically finished and the main hall renovation project of the Sagya Monastery is expected to be completed by the end of this year, according to Tibet local bureau of cultural relics protection.

"Uncertain factors affecting the going of the project defer the completion date," Yu Dawa, head f Tibet Bureau of Cultural Relics Protection said, "We are facing many difficulties when operating, such as the high altitude, unfavorable weather, large work quantity and limited operation area."

"The project also requires a large quantity of human resources," said Yu.

Open bidding for five assistant projects is preparing, but also fails to be finished within this year, according to Yu Dawa.