Banco Santander has reportedly turned down a bid from NatWest for its UK retail banking operations, saying it considered the offer too low.

The proposal, which was advised by Morgan Stanley and UBS, is no longer active, according to sources privy to the development, reported Financial Times.

The offer made by NatWest was reported to be above £10bn ($13.2bn) but below £12bn ($15.9bn).

Santander’s UK subsidiary, which encompasses both retail and commercial banking, reported total equity of £10.4bn ($13.8bn) at the end of the previous year.

In contrast, the valuation for the Polish unit sale was approximately 2.2 times its tangible book value, indicating a higher valuation than that of the overall group.

Santander has also previously rejected a lower offer for its UK ringfenced unit from Barclays.

The bid from NatWest, which would have marked the largest banking transaction in the UK since the financial crisis, comes as the state-backed lender prepares to enhance its domestic market presence.

This expansion is anticipated to occur once the UK government finalises the sale of its remaining £46bn ($61.1bn) stake in NatWest, expected in the near future.

Jose Garcia Cantera, Santander’s chief financial officer, stated last month, “We want to be a relevant bank in the US.”

Recently, Santander agreed to divest approximately 49% of its shares in Santander Polska, its Polish banking unit, to Austrian bank Erste Group for €6.8bn ($7.7bn).

Additionally, Erste will purchase the remaining 50% of Santander Polska’s asset management business (TFI) for €0.2bn, resulting in a total all-cash transaction value of €7bn ($7.9bn).