Real Estate Investment Trusts, travel & leisure and software & IT services shares provided a modicum of stability on Monday, even though the London market stayed marginally in negative territory.The FTSE 100 closed down 0.44% at 6,953.58 with natural resources related shares, especially oil and mining companies, trading lower on the tepid climate endured by oil benchmarks and base metals.Miners Anglo American (down 2.39%), Glencore (2.33%) Vedanta Resources (down 2.64%), Lonmin (down 2.62%) alongside Premier Oil (down 3.55%), and engineering firm Weir Group (down 3.55%) and Amec Foster Wheeler (down 3.11%) summed a dire day for the segments.However, support for the blue chip and mid-cap indices arrived in the shape of REITs and software & IT stocks. Starting with the latter, with a number of REITs reporting positive data and macroeconomic fundamentals being on a decent footing, investors piled in to the segment as JP Morgan analysts issued a raft of positive recommendations.Workspace (up 3.88%) was the highest riser in the segment, as JP Morgan analysts upped its target price to 980p from 920p but kept the share at overweight. Shaftesbury (up 2.45%), Land Securities (up 0.84%), Great Portland Estates (up 1.57%) and Big Yellow Group (up 0.92%) were other beneficiaries of revised targets from JP Morgan. Overall positivity implied, the segment index rose 1.35% or 45.91 points to 3,458.32.As airlines rose with Flybe (up 1.36%), EasyJet (up 0.31%) and IAG (up 1.00%) all in the green, ably supported by hoteliers IHG (up 0.88%) and Millennium & Copthorne Hotels (0.51%) in the face of rising consumer confidence - the travel & leisure segment index rose to 8,873 up 0.75% or 65.32 points.Additional, positivity story came of the back of mergers and acquisitions chatter in software & IT sector. Imagination Technologies (up 6.61%) led the London market after analysts at Liberum tipped it as a possible take-over target given how Intel sold out of the company earlier in the year and Imagination's current discount to its peer group.Electronic design automation companies such as Synopsys, Cadence or IP outfits such as Rambus could be among the potential acquirers, the broker said. The feverish M&A chatter follows confirmation of Monday of Intel's agreement to buy Altera for $54 per share in all-cash transaction valued at around €16.7bn.Finally, Ultra Electronics Holdings (up 2.29%) stock rose after reaching a deal to acquire the electronics products division of Kratos Defense and Security Solutions for $265m (£173.5m). The deal with the US-based radio frequency and microwave systems supplier will increase Ultra Electronics' presence in the US electronic warfare market.Top five sectorsReal Estate Investment Trusts 3,458.32 +45.91 +1.35%Travel & Leisure 8,873.04 +65.32 +0.74%Electronic & Electrical Equipment 4,527.34 +31.91 +0.71%Software & Computer Services 1,557.19 +10.30 +0.67%Nonlife Insurance 2,153.70 +10.84 +0.51%