Speculation swirled again on Tuesday that a merger of China’s second- and third-largest mobile carriers is in the works, but if the news is true, one of the companies involved was apparently left in the dark.

China Unicom said when asked about a possible merger with China Telecom that it has not received any notification from authorities about the matter, according to Caixin.

Chatter of such a merger has been ongoing for some time, including after the two companies simultaneously announced a series of leadership changes last July.

Bloomberg broke the story on Tuesday that regulators were currently reviewing a proposal, citing people familiar with the matter.

After gaining nearly 6% following the Bloomberg story, shares of Unicom were down almost 2% on in Hong Kong trading Wednesday. Telecom shares were down modestly after rising 4% on Tuesday.

Should such a merger come to fruition, the new entity would become the world’s second-largest carrier by subscriber base, behind China Mobile.