London's blue-chip benchmark sheds 57.8 points at 6,396.1 on Monday as investors remain worried about a lack of progress in breaking the political stalemate over the US budget and debt ceiling. Investor skittishness manifests itself in downbeat reactions to positive news from a number of larger market constituents.

Among them is National Express (NEX), which skids 1.7p to 254.7p despite cheering investors with news of its shortlisting for the Berlin Ringbahn rail contract. The £1.3 billion cap train, bus and coach operator hopes to follow up two recent regional rail service contract wins in Germany's populous North-Rhine Westphalia region by clinching the contract to operate Berlin Ringbahn, which is the railway line of the Berlin S-Bahn around the city centre.

Positive news flow from Thomas Cook (TCG) fails to boost shares in the £2.2 billion cap, off 0.5p at 150.7p in a falling market despite a strong run year-to-date. The travel agent, whose fortunes have been revived under chief executive Harriet Green, announces the sale of its Egyptian and Lebanese businesses for £6.5 million in a move sharpening its focus on core businesses. Shares examined the gathering pace of the turnaround under Green's stewardship in detail back in July.

Also heading south is UK and Swedish drugs giant AstraZeneca (AZN), which falls 0.8% to £31.54 on its acquisition of US biologics specialist Amplimmune. The deal, which could cost the acquirer up to $500 million, boosts the Cambridge-based concern?s cancer pipeline.

One large cap in fine fettle however is aircraft engine manufacturer Rolls-Royce (RR.), which ticks up 0.5% to £11.20 as it wins two maintenance contracts from the US government worth a combined $496 million. The company also pleases with news it has secured a $90 million engine repairs agreement with the American navy for its E-2 Hawkeye aircraft.

Over in the food sector, New Britain Palm Oil (NBPO) cultivates a 2.5p gain at 397.5p as the Papua New Guinea-headquartered sustainable palm oil producer announces its participation in an intriguing new joint venture to develop high yielding hybrid oil palms.

Shares in Cranswick (CWK) fall 4.2% to £10.98 as the fresh pork producer warns margin pressure is crimping profits. Analysts downgrade their numbers on news elevated pig prices will lead to flat operating profits for both the first half and full year. Read our in-depth news analysis here.

Fuel technology play Quadrise (QFI:AIM) advances 1.25% to 24.3p on full year results, as we discuss here.

Oil services minnow Plexus Holdings (POS:AIM) slips 2.7% to 255.5p despite confirming a £750,000 contract with Centrica (CNA) to use its POS-Grip well head technology on an appraisal well offshore Norway. This could represent some profit taking after a 44.5% advance in the shares over the last three months.

Oil and gas producer Petroceltic (PCI:AIM) gushes up 2.4% to 147.5p as it announces Algerian state energy firm Sonatrach is exercising pre-emption rights over the proposed sale of an 18.375% interest in the Ain Tsila gas development. Petroceltic says the deal - which will see it receive $20 million up front, $140 million worth of development costs carried, and two more contingent payments of $10 million each - is similar to terms already agreed with a potential third party purchaser. Following the transaction it will have a 38.25% stake.

The market seems surprisingly unperturbed by a trading update from surveillance technology specialist Digital Barriers (DGB:AIM), even though the firm is leaving itself a lot to do to hit full-year targets. Expected £9 million half-year revenue means £21 million of sales are needed in the second half against a backcloth of weaker UK spending but stronger interest overseas. The shares nudge up 0.5p to 153p.

Boiler efficiency kit supplier Sabien Technology (SNT:AIM) leaps 12.5% to 31.5p after sealing a £2.2 million fit-off order with Lincolnshire County Council. This follows the welcome news of the microcap joining the dividend list with a maiden full-year 0.25p per share payout for last year.

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Issue Date: 07 Oct 2013