PARIS, Oct 19 (Reuters) - French food group Danone kept its guidance that it would return to profitable growth in the second half of 2021 even though sales growth slowed in the third quarter, highlighting the challenges facing its new chief executive.

The consumer goods giant, owner of Evian and Badoit water and Activia yoghurt, reiterated it expected its full year 2021 recurring operating margin to be broadly in line with the 14% achieved last year, as it banked on productivity gains and pricing actions to mitigate inflationary pressures.

Danone posted a 3.8% rise in third quarter underlying sales to 6.158 billion euros ($7.2 billion), slightly above analysts' expectations for a 3.6% rise.

This, however, marked a sequential slowdown from 6.6% sales growth achieved in the second quarter and reflected a slower recovery in its waters business, where strong restrictions tied to COVID-19 measures weighed on sales in Indonesia.

The main task for Antoine de Saint-Affrique, the former boss of chocolate company Barry Callebaut who took the reins at Danone in September, will be to boost lagging sales and margins.

($1 = 0.8586 euros) (Reporting by Dominique Vidalon; Editing by Sudip Kar-Gupta)