On a quiet day for corporate news, the market is marginally down with a 0.5% drop in the FTSE 100 to 6,386. The blue chip index is now several weeks into a choppy trading pattern, struggling to revive the massive rally enjoyed between January and March.

Aggreko's (AGK) trading statement gave few surprises, but this is what the market wanted as we discuss in detail here. Reassurance is a positive signal for the emergency power specialist following two profit warnings in 2012.

From power station decommissioning to asbestos removal, service group Silverdell (SID) has responded to a large drop in its share price over the past few weeks with a trading statement. Investors liked news of a strong order book, sending the shares up 5.6% to 16.38p.

Specialist healthcare company BTG (BTG) improved 1.6% to 360.5p after its varicose vein treatment Varisolve was accepted for a full review by the US Food & Drug Administration (FDA). If approved, management expect to launch the treatment during the first half of 2014 into a market that has 40 million suffers.

AC/DC power converter kit developer XP Power (XPP:AIM) continues to face stiff revenue headwinds. Improving trends into healthcare markets from new programme roll outs are promising, but revenue is being offset by fading technology space sales, leaving first quarter trading underwhelming. The shares, down 1.2% to £12, reflect the benign short-term outlook.

Investors looked to get on board bus manufacturer Optare (OPE:AIM), up 10.5% at 0.37p, after the group won a £4 million contract to provide 20 electric buses to Nottingham City Council.

Business telecoms supplier Alternative Networks (AN.:AIM) is still finding growth hard to come by. Staying on track with lowly expectations tells investors all they need about the market's voice squeeze. The shares remain roughly flat at 318.75p thanks to excellent cash generation. Its £15 million cash pile, after a £5 million tender offer, £3.3 million of dividends and a £1.5 million buyback, is a full £2 million more than FinnCap analysts had expected.

Oil services firm Thalassa Holdings (THAL:AIM), which conducts seismic surveys for the oil and gas industry, ticked up 0.8% to 133p despite the dilution implied by a £5.4 million placing at 120p. The company plans to invest the cash in new equipment.

Shares in oil and gas technology microcap Vialogy (VIY:AIM) jumped 15.4% to 1.5p after bagging a contract from Chevron to map subsurface reservoirs below the scope of usual 3D seismic studies. Focused on horizontal drilling projects in the Delaware Basin, Vialogy's QuantumRD kit will be used by the oil major to map geologically aimed at identifying new exploration and development opportunities.

Oil explorer Mediterranean Oil & Gas (MOG:AIM) ticked up 2.7% to 9.5p as a first quarter update revealed considerable progress in planning for high impact exploration in Malta before the end of the year.

Shares in Breedon (BREE) rose 6.6% to 24.25p after the construction materials group greed to buy four quarries from rival Marshalls (MSLH) for up to £19 million. The acquisition is expected to provide an additional 13 million tonnes of mineral reserves and resources to the group and the potential for additional mineral prospects of 5 million tonnes.

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Issue Date: 12 Apr 2013