NEW YORK, July 5 (Reuters) - Payments processor NCR Voyix is exploring the sale of its digital banking business which it hopes will fetch as much as $3 billion, people familiar with the matter said.

Atlanta, Georgia-based NCR Voyix has tapped Goldman Sachs to solicit interest from potential buyers, which include private equity firms and other payments processors, said the sources, who requested anonymity as the discussions are confidential.

Buyout firms TPG and Warburg Pincus are among the parties that have expressed interest in bidding for the digital banking unit, which currently generates roughly 20% of NCR Voyix's annual revenue, the sources said.

They added that a deal is not guaranteed.

NCR Voyix and Warburg did not immediately respond to comment requests. Goldman and TPG declined to comment.

In October, NCR Corp broke into two separate publicly traded companies, with NCR Voyix housing the digital commerce operations and NCR Atleos comprising the business focused on ATMs.

NCR Voyix, which has lost roughly 20% of its value since it started trading as a standalone company last year, currently has a market capitalization of about $4.6 billion, including debt.

The company, which processes about $227 billion worth of transactions every month on its platform, derives most of its revenue by providing software and payment systems to restaurants and retailers. The digital banking unit provides operational software to more than 450 banks and credit unions.

Prior to the separation, NCR Corp had explored divesting the digital banking unit but shelved the sale process after failing to agree on a price with potential buyers, the sources said.

The sale of the digital banking unit would allow NCR Voyix to pay down some of its debt pile, which stands at about $2.4 billion. The unit is on track to generate roughly $220 million of earnings before interest, taxes, depreciation and amortization (EBITDA) this year, the sources said, adding that such businesses are typically valued at multiples of more than 12 times EBITDA. (Reporting by Milana Vinn and David French in New York Editing by Anirban Sen and Matthew Lewis)