FACTBOX - What A&L will give Santander in Britain

LONDON (Reuters) - Spanish bank Santander agreed to buy Alliance & Leicester for 1.3 billion pounds on Monday, saying the deal will give it "critical mass" in Britain.

Santander already owns Abbey, bought for about 8.5 billion pounds in 2004.

Here are some key facts on the combined and standalone businesses:

UK MORTGAGES:

Combined market share of UK mortgages about 12.9 percent.

Abbey market share: approx. 9.4 percent (3rd biggest lender)

A&L market share: approx. 3.5 percent (9th biggest lender)

OTHER UK RETAIL:

Combined market share of UK savings balances 8.1 percent.