Arthur Andersen has agreed to allow most of its US tax partners join Deloitte & Touche.
The move could be the first stage of the break-up of Andersen's US operations.
It follows recommendations from former Federal Reserve chairman Mr Paul Volcker, who is now acting as an adviser to Andersen, that the US tax and consulting practices split from the auditing arm.
Andersen managing partner, Mr Larry Gorrell, said: "This transaction is fully consistent with our commitment to move quickly on the Andersen reforms initiated by Mr Volcker.
"While our firm will retain appropriate tax expertise in a manner consistent with these reforms, Deloitte will provide a significant number of our people with continuing career opportunities and our clients with continued quality service from recognised and respected professionals".
Terms of the agreement were not disclosed. Andersen's non-US operations are forging partnerships with rivals.
PA