(Bloomberg) -- Billionaire John Grayken’s Lone Star is among private equity firms lining up for all or parts of NatWest Group Plc’s Irish retail unit Ulster Bank, according to people familiar with the matter.

Lone Star, which owns Germany’s IKB Deutsche Industriebank AG, and Portugal’s Novo Banco SA, is working with advisers to study a bid for the assets, according to the people, who asked not to be identified as the information is private. Ulster controls a loan book of about 21 billion euros ($25.3 billion).

Lone Star declined to comment.

NatWest’s Irish Bankers Asked to Prepare ‘Carve Up,’ Union Says

Natwest said last year it’s considering “strategic options” for Ulster. Ulster has mostly struggled after helping fund the Irish real-estate bubble more than a decade ago, which resulted in a rescue from the former Royal Bank of Scotland, itself nationalized by the British state. While previous reviews of Ulster’s future have ended without any change, there’s a growing sense the bank may opt to exit, albeit over a number of years, this time.

Labor unions said this week they expected a decision imminently.

“Our strategy for Ulster Bank business in the Republic of Ireland remains unchanged,” Natwest said in a response to questions Friday. “We continue to evaluate the impact of Covid-19 and the challenges to the economy and we are reviewing our strategy appropriately and responsibly in light of these events.”

Irish government officials have begun war gaming how to handle the closing of the unit, with officials examining possibilities such as how Ulster’s performing loan book might be sold and divided up among the domestic banks.

Other private equity firms are also likely to explore bid, with Cerberus interested in buying the loans should they come up sale, Irish Times reported in October.

No final decisions have been made and Natwest could opt against a sale and the buyout firms could decide against bidding.

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