Global bank HSBC's board on Sunday decided to remain headquartered in Britain, following a review launched last year in response to increased regulation and taxation.
"Unanimous Board decision for #HSBC HQ to remain in the UK," the bank said on Twitter.
The move will come as a relief for the City, where concern about the possibility of Britain leaving the European Union is growing as a membership referendum looms.
"London is one of the world's leading international financial centres and home to a large pool of highly skilled, international talent," the bank said later in a statement.
"It remains therefore ideally positioned to be the home base for a global financial institution such as HSBC," it added.
The statement also said, however, that "Asia remains at the heart of the group's strategy," adding that the bank would put particular emphasis on investing further in China's Pearl River Delta and Southeast Asia.
"This reflects increasing shifts in global trade and capital flows to and from Asia, in respect of which Hong Kong will play a pivotal role," it said.
The review began in April, two weeks before a general election, amid growing calls for a crackdown on the banking sector.
The Asia-focused bank's move highlighted concern about government policy to ring fence British bank's retail operations to protect them from its investment divisions.
The board had "asked management to commence work to look at where the best place is for HSBC to be headquartered" amid "regulatory and structural reforms", HSBC chairman Douglas Flint said then in a statement.
HSBC has been based in Britain since 1992 when it took over Midland Bank and shifted its headquarters from Hong Kong to London.
It was founded in Hong Kong and Shanghai in 1865.