The continental businesses are a drag on Barclays’ returns and it wants to sell or close them to focus on more profitable areas.
But it had not expected to sell them so soon – its plan last month anticipated owning the unit for at least another three years.
The arm could be worth more than €2bn (£1.6bn), and represents around 40 per cent of Barclays’ western European assets.
Caixabank’s chief Juan Maria Nin told the Wall Street Journal that he was also looking at buying Catalunya Banc.
Barclays declined to comment.