According to the Financial Times, Santander is hoping to make the move in a bid to raise around Â£3 billion ($4.5 billion) from the listing, but is waiting for an improvement in market conditions before going ahead with it.
Santander has refused to comment about speculation on the flotation of its UK acquisitions, which are made up of Abbey, Alliance & Leicester and stakes in Bradford and Bingley.
The firm is said to be looking to raise money to fund acquisitions and is reportedly closing in on a deal to purchase more than 300 bank branches from Royal Bank of Scotland (RBS).
Last year, competition commissioner Neelie Kroes warned that RBS had to meet European Commission targets to divest some of its assets after the bank was ordered to sell off various divisions following its bailout from the UK government.
"In case RBS does not deliver on its balance sheet reduction targets by 2013, the commission will be able to intervene again and more divestments will be required," she said.
By Asim Shah