PARIS (Reuters) - Exxon Mobil ( XOM ) fulfilled from existing stock all its delivery contracts from its refinery in Port Jerome-Gravenchon in northern France since it was hit by a major fire on Monday, a spokesperson for the company said.

The refinery's staff were working to assess the damage to one of two distillation towers of the oil refinery to see if and when it would be able to operate again after an emergency at the refinery was called off early on Tuesday, the spokesperson said.

She could not specify how long the refinery would be able to honour all delivery contracts from existing stocks with the tower shut down.

The refinery, located in Normandy near the estuary of the Seine river, has two distillery towers and a capacity of 240,000 barrels per day (bpd), making it amongst the biggest in France. It supplies the Ile-de-France region around Paris.

One person out of the five who received medical treatment was still in observation in a local hospital, the spokesperson said.

(Reporting by Forrest Crellin and Inti Landauro; Editing by Emelia Sithole-Matarise)