PARIS - An overnight fire at French cloud computing company OVHcloud, which this week started the process for a potential IPO, destroyed some servers and forced the temporary shutdown of others, its chairman said on Wednesday. 

OVHcloud told clients to activate their disaster recovery plans following the blaze at a data centre in Strasbourg, eastern France.

"Fire destroyed SBG2. A part of SBG1 is destroyed. Firefighters are protecting SBG3. No impact SBG4," founder and chairman Octave Klaba said on Twitter, referring to different units housing servers.

"We don't have access to the site. That is why SBG1, SBG3, SBG4 won’t be restarted today," he added.

The Strasbourg site is one of OVHcloud's 17 data centres in France, out of 32 globally.

The fire risked disruption for some customers.

PR agency Caroline Charles Communication, whose clients include brands such as Thom Browne and Fila in the midst of Paris Fashion Week, said it had lost access to emails.

"We've not lost any data but for now we don't have emails," Caroline Charles told Reuters, adding the company's data was held on a server at another site.

The French government holds national data that is open to the public with OVHcloud. A spokeswoman for an inter-ministerial office for digital services told Reuters that teams were investigating the scale of impact. Its website appeared to briefly go down.

Founded by Klaba in 1999, OVHcloud is the biggest European-based cloud services provider, competing against U.S. giants Amazon Web Services, Microsoft's Azure and Google Cloud, which dominate the market.

French politicians have championed OVHcloud as a possible alternative to U.S. cloud services providers, but it has so far lacked the scale and financial clout to dent their market share.

Klaba said the fire had been extinguished and firefighters were spraying the site with water to cool it down.

"The goal is to create a plan to restart, at least SBG3/SBG4, maybe SBG1. To do so, we need to check the network rooms too," he said in an update shortly after 0900 GMT.

(Reporting by Matthieu Protard and Mathieu Rosemain. Writing by Richard Lough. Editing by Louise Heavens and Mark Potter) ((; +33-1-49495381;))