HANOI (Reuters) -- Vietnam's economic growth quickened to 7.31 percent in the third quarter year-on-year, the General Statistics Office (GSO) said on Saturday.

The processing and manufacturing industry grew 10.05% in July-September from a year earlier, while the services sector rose 7.11% and the agricultural sector was up 1.53%, the GSO said in a statement.

It also revised up second-quarter gross domestic product (GDP) growth to 6.73% from 6.71%.

The Asian Development Bank said on Wednesday it maintained its forecast for Vietnam's growth for this year at 6.8%, and for next year at 6.7%.

The head of the GSO said last month Vietnam would revise up the size of its GDP by 25.4% for the 2011-2017 period.