Guinness Mahon is put up for sale.
Mr David Potter, Guinness Mahons chief executive, played down suggestions that the move was a response to the Japanese banking crisis.
"It is more a response to ebig bang in Japan," moves to open up the Japanese financial services industry.
New management, though, who took charge of the Bank of Yokohama last spring, has decided to concentrate on being a regional Japanese bank - "like Lloyds Bank in this country" and scale down its international interests.
But before Christmas senior figures at Guinness Mahon were stressing the Japanese banks long-term commitment and its value as a financially strong owner which backed its British offshoots policy of providing services for small and specialist companies.
When Bank of Yokohama bought Guinness Mahon in 1989, it was projected as a strong regional bank unaffected by the bad debts that were plaguing Japans big national banks.
Since then, though, property and share prices in Japan have fallen steeply and the entire banking sector has come under pressure.
"It is a good solid local business and fairly conservative," said Mr Potter.
Guinness Mahons activities include the stockbroker Henderson Crosthwaite, which has a big office in a big office on Worcester. In all, the group employs 572 people.
It is for sale as a single entity, including 44 per cent of the jointly owned fund manager Guinness Flight Hambro Asset Management.
No hint was given yesterday of the kind of price the Bank of Yokohama is looking for.