US investment firms Warburg Pincus and General Atlantic have agreed to buy a 50% stake in Banco Santander's $198bn asset management arm, in a move that puts the business on a path toward independence.

Santander said on Thursday the deal values the business at about $2.66bn, and that it will reap a net capital gain of about $910m from the transaction. Precise terms of the deal weren't disclosed, although people familiar with the matter said the US firms together are paying about $1.3bn for their shared stake.