Strong gains for Vodafone were lifting the mobile telecommunications category higher on Monday afternoon as news of M&A activity across the sector boosted share prices.Shares in the Eurozone's largest telecoms group, Telefonica, rose in Madrid today after it was rumoured that US titan AT&T made an eye-watering $93bn bid for the heavily-indebted company.Though the Spanish firm denied the reports, the positive readacross lifted stocks in London with Inmarsat, Mobile Streams and Mobile Tornado making gains.Last week, Vodafone made a preliminary approach for Kabel Deutshland. Both companies did not actually disclose any details but it has widely been reported that the initial approach of €7.0bn (£6.0bn) was brushed off by the German cable operator, causing Vodafone to drop sharply last week.However, speculation of a revised offer has given the shares a lift in recent days though The Sunday Times reported that Vodafone would have to put a whopping €11bn on the table if it wants to take over the German firm, comprising €8.0bn in cash and a debt pile of almost €3.0bn.Top performing sectors so far todayMobile Telecommunications 4,320.79 +2.79%Household Goods & Home Construction 10,526.88 +2.29%Personal Goods 22,191.81 +1.80%Support Services 5,900.52 +1.75%Financial Services 6,583.95 +1.50%Bottom performing sectors so far todayTechnology Hardware & Equipment 996.28 -2.90%Industrial Metals & Mining 1,369.15 -1.55%Oil Equipment, Services & Distribution 22,245.43 -1.07%Forestry & Paper 8,627.86 -0.56%Mining 15,868.91 -0.28%