Stuart Hendel, former head of Morgan Stanley's ( MS) prime services, is in final negotiations to join UBS ( UBS) in New York in the same capacity, the Wall Street Journal reports, citing people familiar with the matter.

Alex Ehrlich in May left the UBS job Hendel now is poised to take. Ehrlich quit UBS to take the job at Morgan Stanley that Hendel was leaving, the Journal reports.

Negotiations with Hendel aren't complete and could still fall through, but an agreement is expected within the week, the newspaper reports, citing people familiar the matter. Hendel and a UBS spokesman declined to comment for the Journal.

The moves mark a rare switch of senior executives between two firms that for years have competed in the business of prime brokerage, according to the Journal. Prime brokerage is the services that investment banks offer to hedge funds.