HANOI (Reuters) - Vietnam's economy grew an annual 6.4 per cent in the third quarter, the fastest pace since the last quarter of 2015 but below the 6.87 per cent clocked in the same period last year, the government said in estimates released on Thursday.

In the nine months to Sept 30, the South-east Asian nation's economy expanded 5.93 per cent, the General Statistics Office said in its report.

The office revised up economic growth for the January-September period of 2015 to 6.53 per cent, from 6.5 per cent in its earlier estimate.

Adverse weather, including drought in the Central Highlands coffee belt and salination in the Mekong Delta food basket, have affected industrial and agricultural productions as well as Vietnam's export and import sectors.

Vietnam's economy expanded 6.68 per cent in 2015, the fastest pace since 2007 and extending growth momentum that started in 2012, when it slipped to 5.25 per cent from 6.24 per cent the previous year.

The government has projected economic growth of 6.7 per cent this year.