Financial regulators in France and Germany are conducting their own inquiries into the controversial bond dealings by Citigroup that are already the subject of a formal investigation in the UK.
Both Germany's BaFin and France's AMF have told the Reuters news agency that they are gathering information on the trades, but have yet to launch formal investigations.
AMF says it was contacted by electronic bond trading platform MTS with reference to Citigroup's market-moving sell-off of EUR11 billion in government paper in the space of two minutes on 2 August. As other traders moved to cover their positions, Citigroup re-entered the market and bought back EUR4 million of the paper at knock-down prices. Estimates of Citi's profits on the trade vary from EUR10 to EUR30 million.
On Wednesday, the UK's Financial Services Authority (FSA) announced a formal probe under its brief to ensure orderly financial markets.
City sources suggest as many as seven financial regulators might be looking into the matter.