The Zoom Leisure centre at the Kodak Sports Ground in Wealdstone is to close at the end of September.
Leisure centre users have been informed that operator Nuffield Health is handing back the lease to owners Kodak, reports the Harrow Observer, but the facilities may stay open.
A Kodak spokeswoman told the Observer: "Nuffield Health has chosen to leave due to commercial reasons and the general maintenance of the property would be carried out by Nuffield Health. Kodak will take back ownership and keep the facility secure. There are no plans to demolish the building."