British economic growth slowed more than expected in the three months to September after the biggest fall in construction in three years, raising the chances that a period of rapid economic growth is coming to an end.

he Office for National Statistics said third-quarter gross domestic product growth slowed to 0.5 per cent, from 0.7 percent in the three months to June. That was a bigger slowdown than many economists had forecasts, with most expecting a small drop to 0.6 per cent.

Output was 2.3 percent higher than a year earlier, compared with a forecast for it to sustain the second quarter's 2.4 per cent rate of growth, and the smallest increase in two years.

Britain's economy was the fastest growing in the G7 group of advanced economies in 2013 and 2014, as it caught up some of the ground it lost after the financial crisis.

But earlier this month the International Monetary Fund forecast growth would slow to 2.5 per cent this year, closer to Britain's long-run average.

The latest growth figures may also give pause for thought to the Bank of England, which had also forecast that the economy would grow by 0.6 per cent in the third quarter.

Although the biggest economic worries over the quarter centred on a stock market tumble in China, the main driver for the fall in British GDP was a 2.2 per cent decline in the domestic construction industry.

The ONS said that unusually wet weather in August may have played a role, and that its quarterly estimate assumed that growth in the sector had bounced back by 1.3 per cent in September.

The ONS's preliminary estimate of GDP growth is based on less than half the actual data that will go into the final estimate published in a couple of months' time.

Services output - the largest part of the economy and by far the biggest contributor to growth - continued to grow strongly, rising by 0.7 per cent on the quarter, its strongest performance since the last quarter of 2014.

Manufacturing output dropped by 0.3 per cent on the quarter and has contracted for three quarters in a row, but overall industrial output was supported by growth in oil production due to fewer maintenance shutdowns than in previous years.

Earlier official data had shown a slowdown in industrial output in August as well as a chunky fall in construction. A subsequent private-sector survey have showed the biggest drop in industrial orders in three years as overseas demand falters.

However, consumer demand has remained solid, with retail sales growing more strongly in the third quarter of the year than in the second.