UK satellite and triple-play provider Sky intends to launch an MVNO on O2's network in 2016 in a deal that includes LTE.
Martin Scott, Head of Analysys Mason's Consumer Services research practice, said: "This move will leave Vodafone and TalkTalk with more apparent under development in their portfolio.
"With a potential tie-up between EE and BT in the works, this move further evolves the UK telecoms market into one of a limited number of converged 'big hitters'.
"Sky could become a market disruptor, especially if BT's appetite for change is dulled by the acquisition of EE.
"BT has a desire for disruption. It has followed the launch of BT Sport with an 'inside-out' business model for mobile operations, with the fixed network playing a leading role in supporting and delivering mobile services.
"By acquiring EE, BT would become the largest fixed operator and one of the largest mobile operators, with little incentive to disrupt the quad-play market (it would have the most to lose).
"Sky has previously proved its ability and willingness to disrupt the telecoms market, notably its low-price high-speed broadband services - quad-play, and converged fixed-mobile services, could be Sky's next logical move."