LONDON, Jan 28 (Reuters) - JPMorgan JPM.N is in talks to take overflow office space in Credit Suisse's empty former offices in Canary Wharf, a source familiar with the matter told Reuters, having outgrown its own European headquarters nearby.

The Wall Street banking giant has said that all staff must return to working in the office five days a week from March, though the source said that negotiations over the extra space pre-dated that policy shift.

Reuters reported in November that JPMorgan was assessing its long-term options for its London base after running out of space at its tower at 25 Bank Street. Options could include building a new tower in Canary Wharf, upgrading its existing tower or moving to the more central City of London.

The source said that renting space at the former Credit Suisse building at 1 Cabot Square is viewed as an interim solution.

UBS Group UBSG.S took on the lease of the Credit Suisse building after acquiring its stricken rival in 2023, later relocating the staff to its own London office in the City. The building is owned by the Qatar Investment Authority (QIA).

UBS declined to comment and a QIA representative was not immediately available for comment.

Bloomberg first reported on the talks, saying that JPMorgan was looking to rent roughly a third of the available space in the building.

(Reporting by Iain WithersEditing by David Goodman)

((Iain.Withers@thomsonreuters.com;))