U.S. cable company Charter Communications shares rose as much as 10% on Thursday after the Wall Street Journal reported a preliminary approach by Verizon Communications about a tie-up, but Reuters sources said no proposal was made.
Speculation over a combination of the two companies has been building steadily since last month, when Verizon Chief Executive Officer Lowell McAdam told Wall Street analysts that such a deal would make "industrial sense."
Analysts and investors have predicted a wave of deals in the telecommunication, media, and cable sectors in the wake of AT&T's planned $85.4 billion takeover of Time Warner (twx). Both AT&T (t) and Verizon (vz) have looked to diversify due to a saturated wireless market.
After hitting a session high of $341.50, Charter shares (chtr) traded up 8% at $335.20, giving the company a market capitalization of $103.6 billion. Verizon shares fell 1% at $49.20, giving the company a market capitalization of $200.7 billion.
The Journal reported it was unclear if Charter's executives would be open to a transaction and that there was no guarantee a deal would be struck.
Charter and Verizon declined to comment.
Verizon had a market capitalization of $203 billion as of Wednesday's close, while Charter was valued at nearly $84 billion, according to Thomson Reuters data (tri).
A Verizon-Charter combination would bring together Verizon's more than 114 million wireless subscribers with Charter's cable network, which provides television to 17 million customers and broadband connections to 21 million, the Journal said.
Get Data Sheet, Fortune’s technology newsletter