Royal Bank of Scotland has urged ABN Amro to abort the sale of LaSalle Bank after throwing down the gauntlet in the world's biggest banking takeover battle with an indicative bid for the Dutch bank that topped the $100bn (€73.6bn) mark and could derail an agreed deal with Barclays.

RBS and its consortium partners, Banco Santander and Fortis Group, this morning stepped out of the shadows to outline for the first time details of their potential bid for ABN Amro. The move comes after Barclays on Monday agreed a takeover of the Dutch bank that included the sale of the LaSalle business in the US to Bank of America.