UPDATE 1-Supermarket retailers Casino, Auchan enter purchasing partnership talks

* Follows last week's Monoprix deal with Amazon

* Competition intensifying in French sector(Adds detail, background)

PARIS, April 3 (Reuters) - French supermarkets Casinoand Auchan have begun talks on a forming apartnership regarding the purchasing of food and non-food items,as competition intensifies within the domestic sector.

The companies said on Tuesday that they were in talks tojointly negotiate purchases with their main, multi-national foodand non-food suppliers.

Casino's planned partnership with Auchan in this area comesjust a week after it struck a deal with Amazon.

Casino and Amazon said last week that groceries sourced fromCasino's Monoprix supermarket arm would be available through theAmazon Prime Now app and website.

Amazon's purchase of the bricks-and-mortar retailer WholeFoods Market Inc for $13.7 billion last year, along with a dealfor Amazon Prime to sell products from the British supermarketchain Morrisons, have led to speculation that Amazoncould bid for a retailer or form a partnership in France.

Casino already has another delivery partnership with UKonline retailer Ocado, signed last year.

In January, Casino's French rival Carrefour alsosaid it would seek a partnership in China with Tencentin the face of competition from Amazon.(Reporting by Sudip Kar-Gupta, editing by Larry King)