The Council of Mortgage Lenders' annual list of top lenders names HBOS as the biggest lender for the second year running, both by size and by total mortgage assets in 2003.
HBOS' estimated market share of gross mortgage lending in the year is 26.0%, while Abbey's is 10.7%.
If HBOS was to be successful in a bid for Abbey it could boost its total market share to 30.7%. Deutsche Bank says HBOS is expected to emerge the victor from the looming takeover battle.
In a comprehensive research note entitled HBOS, best dressed for the Abbey ball, Deutsche analyst Nick Lord says that HBOS is the only UK bank likely to counter the agreed offer tabled by Spain's Santander Central Hispano.
Lord says: “We believe it is increasingly likely that HBOS will counterbid for Abbey and that it is the only UK bank with a serious chance of success.
“Although it is possible that others might enter the fray, the regulatory hurdles would be higher so we believe that HBOS will be the only serious counterbidder.”
HBOS was thought to be taking advice on how monopoly watchdogs would respond to a combination of the two British banks following Lloyds TSB's attempt to buy Abbey.
CML figures show HBOS is again top lender by far, with £171.7bn of mortgage balances outstanding at end of year and an estimated 22.5% market share. HBOS' gross mortgage lending in the year has been £70.3bn and it is estimated to have a 26% market share.
Abbey National comes second on the CML table, with total mortgage balances outstanding at end of year at £88.2bn and gross mortgage lending of £29.1bn.
The top five lenders were Abbey, Nationwide, Lloyds TSB, Barclays, and The Royal Bank of Scotland.
Barclays has slipped two places in the table since last year, while Nationwide has moved up two places to become the country's third biggest lender.