(Bloomberg) -- A Turin court on Tuesday accepted a request from the Elkann family to suspend an inheritance case that’s pitted Stellantis NV and Ferrari NV Chairman John Elkann against his mother Margherita Agnelli and threatened to call into question the billionaire clan’s control of its business empire.  

Margherita Agnelli, 67, has challenged agreements on the inheritance from her father Gianni Agnelli, Italy’s most prominent postwar industrialist and at one time the country’s richest person, and her mother Marella Agnelli. Her claims are based on doubts about her mother’s legal residence at the time of her death. Margherita Agnelli is Gianni Agnelli’s last surviving child. 

Margherita Agnelli has claimed that inheritance pacts that effectively closed out her position in family business were not valid since Marella was a legal resident in Italy when she died, not in Switzerland, as official documents stated at the time. Marella Agnelli died in 2019 at the age of 91. If Margherita Agnelli can ever establish that her mother’s formal residence was in Italy rather than Switzerland, it could alter the inheritance provisions, as Italian law doesn’t allow inheritance rights to be waived before a person’s death. 

The court on Tuesday ruled that the case should be suspended pending the process of trials currently underway in Switzerland, according to a copy of the ruling seen by Bloomberg. At the same time, the Turin court rejected an Elkann request to dismiss the Italian proceedings entirely and shift the full case to Switzerland. 

Margherita Agnelli has already spent more than a decade contesting her father’s will, claiming that provisions were only made for the three children from her first marriage, John, Lapo and Ginevra Elkann. Margherita has another five children from her second marriage, to former Fiat manager Serge de Pahlen. 

A spokesman for Elkann, the handpicked successor to longtime Fiat boss Gianni Agnelli, declined to comment. A representative for Margherita Agnelli also declined to comment. 

The stakes in the case could potentially include control of Dicembre Societa Semplice, the Elkann siblings’ vehicle which sits at the top of the Agnellis’ chain of investments. The disputed holding controls the Giovanni Agnelli BV vehicle, which in turn sits atop the listed Exor NV. Giovanni Agnelli BV’s stake in Exor is worth about €10 billion ($10.7 billion). 

Amsterdam-based Exor controls Ferrari and CNH Industrial NV and is the biggest investor in Stellantis.

Following the 2003 death of her father, Margherita Agnelli sold her 37.5% stake in Dicembre for about €105 million. But after Fiat was resuscitated by Chief Executive Officer Sergio Marchionne, she sought to nullify the accord. 

(Updates with residence in third paragraph, Elkann request in sixth.)

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