Vodafone shares hit a 14-year high yesterday on the back of potential merger activity.
Vodafone rose almost 5pc to 253.75 pence each, following upgrades from Citi and Deutsche Bank.
Both brokers cited comments earlier in the week from Liberty Global chairman John Malone that Vodafone would be a "great fit" for his company, which already owns UPC in Ireland.
Vodafone shares are widely held in Ireland as a result of its deal to buy Eircell 15 years ago.
The stock is up 12pc since Wednesday. Goldman Sachs said it believed the company was considering a range of options.
"There is significant industrial logic in fixed/mobile M&A on a market-by-market basis," analysts at Goldman said in a note, reiterating a "buy" rating on the stock.
"(Vodafone) is willing to consider both acquisitions and disposals where the financial rationale makes sense."
Vodafone is the world's second-biggest mobile operator. Liberty is Europe's largest cable operator. The market is increasingly moving towards the combination of mobile services with fixed-line broadband.
On Tuesday, Vodafone chief executive Vittorio Colao declined to comment on the prospect of a deal with Liberty. "We have our own strategy," he said.