Citigroup is partnering with Euroclear and Clearstream to combine client holdings into a single collateral pot to cope with more stringent trading rules, Financial News has learnt.

Under the arrangement, Citi will make securities that it holds in custody for mutual clients available for use as collateral by Euroclear and Clearstream. The assets remain under Citi's custody, and the tri-party agents manage the collateralisation process directly from client trading accounts.