Shares in Casino – the French grocery giant that has partnered with Ocado – and its parent company Rallye have been suspended as concerns mount over their debt piles.

The move sparked speculation that a debt restructuring plan could be imminent.

Casino’s total debt stood at €2.7bn at the end of 2018, while Rallye’s was €2.9bn.

Any deal to restructure those debt piles could raise questions over the future of Casino chair and chief executive Jean-Charles Naouri.

Casino struck a deal to license Ocado’s technology and logistics in November 2017. The partnership includes the construction of an automated warehouse to serve the Greater Paris area, as well as the Normandy and Hauts-de-France regions.

Casino said at the time it would initially leverage the Ocado Smart Platform on its Monoprix website, to provide its customers with “the largest assortment of food items at the best levels of service and costs”.

It plans to use the technology across more of its banners in the future.

Prior to today’s suspension, shares in Casino slumped 6.4%. Its value has now fallen by around a fifth since the turn of the year.

Rallye, which owns a 51.7% stake in the grocer, is in turn controlled by Fonciere Euris, Finatis and Euris. Trading in all three of those companies was also suspended today.

Bernstein analyst Bruno Monteyne said: “The suspension of the parent company shares suggest that a form of debt restructuring will have to take place in those companies.”

He added that such a restructuring “leads probably to Mr Naouri losing majority shareholder control of the holding companies”.

Casino’s credit rating was downgraded by Moody’s in April, a month after it was pushed further into junk status by Standard & Poor’s.

The retailer has been selling assets in a bid to slash its debt and shore up its balance sheet.