A French court has ordered Ryanair to pay over €8 million in fines and damages over labour code breaches linked to treatment of local workers hired on foreign contracts.
Ryanair faced charges covering a range of alleged labour code violations connected to its Marseille operating hub between 2006 and 2010.
The court in southern France ordered Ryanair to pay €200,000 of fines, in addition to €4.5m of backdated social charges, €3m in pension contributions and €450,000 in unemployment charges.
The court found that Ryanair had breached the labour code by not paying French social and other charges for workers hired abroad but who spent much of their time at the Marseille hub.
Ryanair has confirmed it will appeal the ruling.
The airline said it believes there is a "clear contradiction between EU employment regulations under which these Irish workers paid their taxes and social taxes in Ireland, and the 2006 French decree".
It said the decree requires "airline crews operating in Ireland to pay social taxes and pension contributions in France, despite the fact that they have already paid them in Ireland".
Ryanair said it intends to pursue its appeal all the way to the European Courts.
Ryanair has since shut its permanent Marseille hub and operated a summer-only operation since April 2011.
Earlier, Ryanair reported a 3% rise in passenger numbers for September.
The airline said it flew 8.10 million passengers last month, up from 7.84 million the same time last year.
Its load factor, which is how many seats it fills on each flight, rose to 85% from 84%.