A banker involved in the deal told Bloomberg that the ten-year notes will pay a yield of 90 basis points more than the mid-swap rate.
The banker said that Santander had increased the yield from the original offer of 85 basis points.
Suki Mann, a credit strategist at Societe Generale SA in London, said: "Santander wants to make sure that the deal gets away well. The market is weaker over the past couple of sessions because of the banks in America."
The banker, who wouldn't give his name before the deal was confirmed, said that Santander also plans to sell $1 billion of undated bonds later this week.
A consortium led by the Royal Bank of Scotland, won their bid to buy ABN Amro last week, Fortis and Santander are the other member of the bid.