HONG KONG (Reuters) - Chinese oil major PetroChina Co Ltd <0857.HK> reported a 26 percent drop in fourth-quarter net profit on Thursday, lagging forecasts, as strong upstream gains were offset by massive losses at its refining segment.

PetroChina <601857.SS> , the country's dominant oil and gas producer that also owns refineries, posted a fourth-quarter net profit of 29.55 billion yuan ($4.69 billion), down from 40 billion yuan in the same period in 2010, based on Reuters' calculations.

The result compared with a forecast of 35.17 billion yuan, according to Reuters calculations.

For the full year, the state-run company posted a net profit of 132.96 billion yuan, versus 139.99 billion yuan in 2010. The result compared with a consensus forecast of 138.58 billion yuan from 31 analysts polled by Thomson Reuters I/B/E/S.

($1 = 6.3060 Chinese yuan)

(Reporting by Charlie Zhu and Alison Lui; Editing by Muralikumar Anantharaman and Chris Lewis)