Adds details on the agreement, quotes from ING Spain CEO, global head of private banking, details from paragraph 4

By Mateusz Rabiega

July 6 (Reuters) - Netherlands-based lender ING INGA.AS said on Monday it would buy a stake of about 40% in Spain's Singular Bank from private equity firm Warburg Pincus for an undisclosed price, as it seeks to expand its private banking and wealth-management divisions across its markets.

The purchase, plans of which were first reported by Spanish newspaper Expansion last week, is expected to be finalised in the first quarter of 2027. Singular has around €19 billion ($22 billion) worth of assets under management, ING said.

Italy's Intesa Sanpaolo ISP.MI had also been interested in Singular, sources told Reuters in May, confirming an earlier Financial Times report which said Warburg was seeking €300 million for its entire stake.

Under the agreement, U.S.-based Warburg Pincus will exit Singular, with ING obtaining a non-controlling stake.

The remaining shares would be divided between Mexican financial services provider Actinver ACTIVCRB.MX, Spanish private equity firm ProACapital and a number of local family offices, ING Spain CEO Alfonso Tolcheff Vaca De Osma told Reuters.

Singular's management, led by former Santander CEO Javier Marin, is also expected to increase its stake to 15% following the transaction, he added.

The parties also agreed to allow for a potential reassessment of the ownership structure in the future, giving the Dutch lender the option to increase its stake in Singular, ING said.

PRIVATE BANK GROWTH

ING has been working to increase its net fee and commission income in recent years, focusing on the growth of its private banking, investments and wealth-management arm.

The lender's private banking services are now available to clients in the Netherlands, Belgium, Poland and Luxembourg, with further launches expected in Italy and Spain later this year.

Anneka Treon, ING's global head of private banking, wealth management and investments, said that while the bank does not have a private banking presence in Germany, a potential move "could be interesting," more than a year after CEO Steven van Rijswijk said ING was targeting growth in the country.

($1 = 0.8758 euros)