Feb 14 (Reuters) - Avaya Holdings Corp has filed for Chapter 11 bankruptcy and secured a financing of $780 million as it restructures its business, the IT firm said on Tuesday.

Avaya said upon completion of the restructuring process it will reduce its total debt by more than 75%, from nearly $3.4 billion to about $800 million.

The new capital is "expected to provide substantial liquidity to support Avaya during the process and beyond," it said.

The cloud communications company added it would continue to serve its customers and partners without interruption and expects to complete the process in 60 to 90 days.

Avaya had said there was substantial doubt about its ability to continue as a going concern in light of a debt maturity in 2023, according to a Wall Street Journal report in December, which cited people familiar with the matter.

Earlier in September, Avaya has also announced restructuring, including job cuts, to reduce costs. Avaya's shares have fallen nearly 99% last year.

Evercore Group is serving as financial advisor to Avaya for the process.

(Reporting by Tiyashi Datta in Bengaluru; Editing by Shailesh Kuber)

((tiyashi.datta@thomsonreuters.com;))