Leeds Building Society made its record operating profit last year.
2011 also saw the mutual’s membership and savings balances reaching their highest ever levels.
Operating profit increased by 21% to £102.4 million, while its pre-tax profit rose by 19% to £50.2 million.
New residential lending increased by 25% to £1.23 billion and savings balances grew by £329 million to a record level of £7.4 billion.
The average loan to value (LTV) on 2011 advances was 51% compared to 53% in 2010.
Peter Hill, chief executive, said: “Leeds Building Society has again delivered an excellent set of financial results and provided even more capacity in the UK mortgage market