Voafone, the world's largest mobile telecommunications company, saw its shares lift after better-than-expected first quarter results for Verizon Wireless, its US joint venture with New York-based Verizon Communications.
Shares peaked at 173.131 shortly after 13.00pm GMT, up from an opening price of 172.40.
"Verizon Wireless produced both great growth and great margins," Lowell McAdam, Verizon chairman and chief executive, said.
Service revenues for Verizon Wireless, which is the largest US wireless carrier, were up 7.7 percent on the year for the first quarter of 2012, to $15.4bn (£9.58bn).
Retail service revenues grew 8.9 percent, to $14.9bn. Data revenues were $6.6bn, up 21.1 percent.
Total revenues were $18.3bn, up 8.2 percent. Its profit margin rose quarter-on-quarter to 46.3 percent, from 42.2 percent.
The company also reported that it added 734,000 retail net customers in the quarter, taking the total customer base to 93m retail customers - year-on-year growth of 5.2 percent.
Vodafone owns 45 percent of Verizon Wireless, which was set up in 1999.
There is ongoing speculation that Vodafone will one day be the subject of a takeover by Verizon Communications.
In March Morgan Stanley analysts had pointed to a Verizon takeover because Vodafone's share price is better and would be a way of closing a $100bn valuation gap in the pair's joint venture, Verizon Wireless.
"This leaves an acquisition of Vodafone by Verizon as the classical solution to a valuation disparity of this sort," said a Morgan Stanley to the Guardian.
"Vodafone shareholders would likely require a significant portion of consideration in cash.
"A new Verizon levered at 3 times could in theory raise $100bn for such a transaction, but whether such a large amount can be raised today in practice is uncertain.
"Any share consideration would be subject to valuation and flow-back concerns, though this could be mitigated by a local listing."
Others ruled out a takeover.
"This mismatch in valuation, coupled with a healthier outlook for Vodafone's business against Verizon's wireline, means the Vodafone board would be highly unlikely to accept [a stock deal]," Bernstein Research analyst Craig Moffett wrote in a memo to his clients, which is quoted by Forbes, adding that Verizon outright buying Vodafone "also appears to be impossible to finance".