(Reuters) -The U.S. Federal Trade Commission sued to block Edwards Lifesciences Corp's acquisition of JenaValve Technology Inc, saying in a lawsuit filed in Washington on Wednesday the merger would decrease competition in the market for a device meant to treat a potentially fatal heart condition.

Edwards and JenaValve are the only two companies in the U.S. currently conducting clinical trials on transcatheter aortic valve replacement devices, which are used to treat a condition called aortic regurgitation where the heart's aortic valve does not close properly, the FTC said in its lawsuit.

Edwards said it "disagrees with FTC's decision and believes it will limit the availability of an important treatment option for patients suffering from aortic regurgitation." It expects a final outcome by early 2026.

Edwards announced the deal in July 2024, along with its acquisition of another heart valve maker, Endotronix. The deals, together valued at approximately $1.2 billion, were aimed at expanding its portfolio of structural heart disease treatments.

(Reporting by Jody Godoy in New York; Editing by Emelia Sithole-Matarise)