French economic growth slowed slightly more than expected in the first quarter as business investment and exports eased, a first estimate from the INSEE statistics agency said. 

The euro zone's second-biggest economy grew 0.3% in the first three months - the slowest rate since the third quarter of 2016 - after expanding 0.7% in the final three months of last year, INSEE said. 

Economists had on average expected growth of 0.4%, with forecasts ranging from 0.2-0.6% in a Reuters poll of 30 economists. 

Consumer spending growth, traditionally the main motor of the French economy, grew only 0.2% in the first quarter despite exceptionally cold temperatures boosting energy consumption, the same rate as in the previous quarter. 

Meanwhile businesses slowed investment growth to 0.5% from 1.6% in the previous three months, while exports dipped marginally after a spike in the previous quarter. 

Since imports were flat, foreign trade had no impact on overall growth.