"We are now covering all of Paris and we are working on a roll out with Amazon whose sole geographic constraint is the presence of Monoprix stores," Regis Schultz told a news conference on the 2018 results of parent Casino.

Meanwhile, Casino CEO Jean-Charles Naouri said the partnership with Amazon had enjoyed an "excellent" start in Paris, exceeding "what had been budgeted". He did not provide further details.

Monoprix, seen by analysts as similar to U.S. retailer Whole Foods which Amazon bought last year, started filling orders for subscribers to Amazon's Prime loyalty programme in parts of Paris on Sept. 12 through a two-hour delivery partnership.

The performance of the alliance is being closely watched since Monoprix was the first French retailer to agree in March 2018 to sell its products via Amazon, causing a stir in the fiercely competitive domestic French market.

The U.S. E-commerce giant, which has run its Amazon Prime express delivery service in Paris since 2016, has made no secret of its desire to launch a grocery delivery service in France as part of its ambitions to expand in food retail.

(Reporting by Dominique Vidalon; Editing by Sudip Kar-Gupta)