UPDATE 1-Canadian Natural faces another oil sands cost jump

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TORONTO, Aug 6 (Reuters) - The cost of Canadian Natural Resources Ltd's (CNQ.TO) Horizon oil sands project has jumped another 6 percent to nearly C$9.3 billion ($8.8 billion) and start-up has been pushed back due to struggles getting processing units ready, the company said on Wednesday.

Canadian Natural, the country's No. 2 independent oil explorer, said the first 110,000 barrel a day phase of the development is now expected to start up sometime after the third quarter.

Production had been targeted for before the end of September and some investors had expected the development to start up this month.

At the new estimate, the project -- Canada's fourth oil sands mining operation -- is 36 percent over the original C$6.8 billion budget set in 2004.

However, nearly all new projects and expansions in Alberta's oil sands have suffered overruns due to a stretched labor force and inflation in the cost of materials, especially steel, amid a rush to tap the huge resource.

Canadian Natural said it was suffering delays getting the oil sands upgrading and hydrotreating plants ready for operations. They help turn the heavy crude from the oil sands into refinery-ready light oil.

The company is scheduled to discuss the project and its second-quarter results in a conference call on Thursday.

($1=$1.05 Canadian) (Reporting by Jeffrey Jones; editing by Carol Bishopric)