Following reports the Vodafone (VOD) is exploring a possible combination with Liberty Global (LBTY), UBS has said the UK telecoms group may have to wait until its shares rise before undertaking such a sizeable deal.The bank kept a 'buy' rating and 265p target price for the London-listed stock.Bloomberg this week cited sources who said that Vodafone is considering a tie-up with the US media giant to create a full-service European phone, internet and TV company valued at over $130bn.The speculation follows the news that rival telco BT is looking at buying either O2 or EE in the UK."Near-term, we think the focus for VOD is on driving organic growth, integrating recent acquisitions and executing on Project Spring [investment programme]. Until the VOD share price is notably higher, it may be difficult for VOD to undertake a transformational deal," UBS analysts Polo Tang and Michael Hill said.While they still see "clear strategic logic" in the deal, its size and timing may be negative for investor sentiment at Vodafone.A "more convenient solution" in the near term may be the rumoured 'industrial alliance' with Sky, they said."A LBTY deal would give VOD critical mass in fixed line in the UK, Netherlands and Germany, although there could be regulatory issues in Germany - we calculate cost synergies could be over £1bn per annum (with an net present value of over £9bn)," Tang and Hill said."A Sky deal would give VOD differentiated content in the UK, Italy and Germany as well as a fixed line solution in the UK - we estimate cost synergies could be over £500m per annum (with an net present value of over £4bn)."Vodafone's shares were up 1% at 229.55p by 10:04 on Tuesday.