First Union, whose UK subsidiary Burdale Finance is backing the Phoenix takeover of Rover, is a fast-growing US regional bank.

It is now America's sixth largest bank, with a strong base in retail banking on the East Coast.

The bank, with its headquarters in Charlotte, North Carolina, has expanded rapidly in the last 15 years through mergers and acquistions, taking advantage of changes in US banking law.

Its assets have grown from $7.3bn to $253bn in that period, while it has a market value of $31bn.

The bank first moved into other Southern States, acquiring banks in Florida, South Carolina, Georgia, Tennessee, and North Carolina.

In 1993 it moved into Virginia and Washington, DC, but the biggest deal was in 1996 when the company merged with First Fidelity Bancorporation, adding states of New Jersey, Pennsylvania, New York, Connecticut and Delaware.

Philadelphia merger

In 1998, expanded Northeast reach through another merger with CoreStates Financial of Philadelphia .

The bank became a nationwide brokerage with the acquisition of Chicago-based Everen Capital Corporation.

Through its acquisitions, First Union has grown into one of America's largest banks from only 50th position fifteen years ago, as the US banking industry has rapidly consolidated.

It has built itself into the eighth largest securities business in the US and is the sixth largest broker, with brokerages in 41 states.

It is also a leading asset manager and a leading provider of insurance products.

First Union has also made headways into online banking.

The bank says that its efforts to expand its client base throughout the East Coast have given its the largest domestic deposit share from Connecticut to Florida, with nearly 16 million customers.