The first surprise is a US banking deal that does not involve a target mauled by subprime lending. The second is that the would-be buyer is Japanese. Mitsubishi UFJ wants to buy the 35 per cent it does not already own of UnionBanCal for $63 a share, implying a valuation of $8.8bn for the owner of Union Bank of California. Relatively unscathed, Japanese banks have already lent a financial hand to struggling global peers. MUFJ has bigger plans.

Majority-owned by MUFJ since 1996 and with a chief executive who hails from its controlling shareholder, UNBC has maintained strategic independence. With more than 300 branches focused on commercial lending, the bank steered clear of the worst of the mortgage mess. Its shares have outperformed a battered sector, rising almost 20 per cent this year even before MUFJ announced its offer.