Sprint and T-Mobile have nixed their merger.

In a brief joint statement Saturday, the companies said they were "unable to find mutually agreeable terms."

The move wasn't a surprise. A Monday report by Japanese publication Nikkei said Sprint's parent company, Japan-based carrier SoftBank, planned to break off merger talks because of a dispute over ownership of the combined company.

The report said SoftBank and T-Mobile's parent company, German carrier Deutsche Telekom, had reached a broad pact but hadn't agreed who would control the merged entity. Deutsche Telekom reportedly had insisted on a controlling stake, something SoftBank initially was open to but then reconsidered, Nikkei said. Deutsche Telekom declined to comment on that report, and SoftBank didn't respond to a request for comment.

A possible merger between T-Mobile and Sprint has been rumored for years but has failed to materialize. The two companies lag behind their bigger rivals, Verizon Wireless and AT&T, when it comes to the US market. Combining would give them an advantage, but critics fear having three players would reduce competition and hurt consumers.

Sprint and T-Mobile both said Saturday that they had no additional comment to make about the end of the merger talks.

CNET's Shara Tibken contributed to this report.