NEW DELHI, July 29 (Reuters) - Russia-backed Indian

refiner Nayara Energy, recently sanctioned by the European

Union, has turned to domestic firm Rediff.com after the U.S.

tech giant Microsoft ( MSFT ) suspended IT services, three

sources familiar with the matter said.

Nayara, which has condemned the sanctions, said on Monday it

had filed a case against Microsoft ( MSFT ) in the Delhi High Court over

its withdrawal of services.

Nayara, a major buyer of Russian oil that is 49% owned by

Russian oil major Rosneft, has struggled with

disruptions since coming under European Union sanctions this

month targeting Russia over its war in Ukraine, including

trimming refinery runs.

Sources told Reuters that since last Tuesday, Microsoft ( MSFT )

had halted services for Nayara, and that employees' Outlook

email and Teams messaging accounts had not been working.

The Rediff.com service can facilitate communications

among Nayara employees but cannot retrieve data and previous

emails stored on Microsoft's ( MSFT ) cloud, sources said.

The sources spoke on condition of anonymity as they were not

authorised to speak to media.

Nayara and Rediff did not immediately respond to requests

for comment.

Mumbai-based Rediff offers online consumer services and also

provides cloud-based email services for businesses.