London's leading shares ended with heavy losses as concerns about the global economy resurfaced again. Traders were nervy in Europe about bank payments that need to be made to the European Central Bank this week, while triple-digit falls on Wall Street added to London's woes. As in London, US investors are concerned that China's economy is not likely to grow at the rate previously anticipated. US based research group the Conference Board said overnight that its China leading economic index rose just 0.3% in April, a sharp revision down from its preliminary estimate of a 1.7% rise. The news hit miners the most in London, especially Xstrata, Rio Tinto, Vedanta, Lonmin and ENRC. Things are only marginally less bad among oil stocks where Tullow Oil and oilfield services firms Petrofac and AMEC were under pressure. Travel stocks were also under pressure, such as Carnival and BA.In the circumstances, the share price decline of BP does not look so drastic. The beleaguered oil giant said its attempts to clean up the oil spill in the Gulf of Mexico may be hampered by tropical storm Alex. The storm has already prompted some companies to evacuate workers from some offshore rigs in the Gulf.JPMorgan has floated the idea of US oil behemoth Exxon Mobil bidding for its crippled UK rival and thinks an offer of 473p per BP share might win support.US companies are interested in UK assets judging from Emerson's 375p per share or £1bn bid for Chloride this morning. It trumps an agreed 325p offer from ABB by 15%. ABB is considering its position. The prospect of a bid from the US is also shoring up the share price of drugs titan AstraZeneca. Credit ratings agency Standard & Poor's has named Astra, along with infrastructure contractor Balfour Beatty and UK defence firm BAE Systems as companies on the radar of cash rich US companies seeking to take advantage of the strong $/£ exchange rate.Advertising giant WPP Group said revenues, profits and operating margin in the first five month of the year are 'well ahead'. On a like-for-like basis, excluding the impact of acquisitions and currency fluctuations, revenues were up 2%.Outsourcing specialist Serco remains on course to meet guidance given in May, although it gave no clue as to the possible impact of spending cuts announced in last week's Budget. Shares in Connaught continued to slide on Tuesday, having fallen by a third on Friday and another third yesterday. Connaught's shares started their descent on Friday after the social housing firm lowered its estimates for this year and next year because of the emergency budget.Bus and train group National Express expects first half pre-tax profits to show good progress after trading was in line with forecasts through the second quarter. Revenue trends have been resilient, whilst progress on cost saving programmes and delivery of a stronger operational focus across the business has accelerated, it added.Things are on the up at floor coverings retailer Carpetright though not the share price even though revenue and profits both improved last year. Profit before tax came in at the lower end of expectations and the dividend rise was less than expected. Downbeat broker notes also added to selling pressure.Asia focused oil explorer Salamander Energy has abandoned the Tom Su Lua-1X exploration well in the Vinh Chau Graben system, offshore southern Vietnam, as a dry hole.Catlin plans to form a reinsurance company in Switzerland to expand the European-based reinsurance business underwritten by the Bermuda-based group. The group has applied to the Swiss Financial Market Supervisory Authority (FINMA) to establish Catlin Re Switzerland, to be headquartered in Zurich.A weaker than expected flu season will mean first half underlying revenues at in vitro diagnostics firm Axis-Shield rising by just 2%.Womenswear clothing retailer Jacques Vert bounced back into the black last year and to celebrate the company is proposing a dividend for the first time since 1995. Profit before tax was £5.12m compared to a loss of £2.86m the year before.The share price of Infrastrata, the company formerly known as Portland Gas, ballooned after it said it is setting up a number of joint ventures with US energy company eCORP so the two can co-operate on gas storage. Guildford-based fuel cell developer AFC Energy said it has successfully deployed an alkaline fuel cell system at Linc energy's underground coal gasification (UGC) demonstration facility in Chinchilla, Australia. FTSE 100 - RisersEssar Energy (ESSR) 459.20p -0.17%British Sky Broadcasting Group (BSY) 703.00p -0.28%Smith & Nephew (SN.) 636.00p -0.31%Diageo (DGE) 1,060.00p -0.38%AstraZeneca (AZN) 2,947.00p -0.49%BT Group (BT.A) 130.70p -0.61%Tesco (TSCO) 390.65p -0.81%Capita Group (CPI) 760.00p -0.91%Severn Trent (SVT) 1,228.00p -0.97%Associated British Foods (ABF) 976.50p -1.01%FTSE 100 - FallersRio Tinto (RIO) 3,048.00p -6.39%Barclays (BARC) 267.35p -6.31%Xstrata (XTA) 908.70p -6.07%British Airways (BAY) 197.00p -5.92%Lonmin (LMI) 1,455.00p -5.89%Antofagasta (ANTO) 798.50p -5.84%BHP Billiton (BLT) 1,772.00p -5.82%Carnival (CCL) 2,154.00p -5.82%Petrofac Ltd. (PFC) 1,166.00p -5.43%Eurasian Natural Resources (ENRC) 898.00p -5.27%FTSE 250 - RisersChloride Group (CHLD) 387.10p +11.08%Mcbride (MCB) 126.30p +4.38%Domino Printing (DNO) 461.00p +2.44%JD Sports Fashion (JD.) 756.00p +1.48%Supergroup (SGP) 742.50p +1.30%Dignity (DTY) 647.00p +1.09%PZ Cussons (PZC) 332.40p +0.76%Eaga (EAGA) 114.20p +0.62%RPS Group (RPS) 188.90p +0.37%Mitie Group (MTO) 212.80p +0.28%FTSE 250 - FallersConnaught (CNT) 107.20p -20.59%Cookson Group (CKSN) 384.50p -10.12%Carpetright (CPR) 640.00p -9.86%Hansen Transmissions International (HSN) 70.55p -8.14%Ashtead Group (AHT) 90.85p -7.77%Enterprise Inns (ETI) 91.55p -7.53%Yell Group (YELL) 24.70p -7.00%Persimmon (PSN) 361.00p -6.67%SIG (SHI) 103.50p -6.59%Aquarius Platinum Ltd. (AQP) 342.50p -6.52%FTSE TechMARK - RisersAsterand (ATD) 13.25p +8.16%RM Group (RM.) 169.00p +6.29%Gresham Computing (GHT) 16.00p +4.92%Phytopharm (PYM) 8.38p +4.42%Innovation Group (TIG) 11.75p +2.17%Skyepharma (SKP) 27.50p +1.85%Electronic Data Processing (EDP) 47.00p +1.06%Biocompatibles International (BII) 261.50p +0.38%Psion (PON) 75.00p +0.33%Wolfson Microelectronics (WLF) 172.00p +0.29%FTSE TechMARK - FallersAEA Technology (AAT) 15.50p -13.89%Vislink (VLK) 22.25p -5.62%Intec Telecom Systems (ITL) 52.00p -5.45%Filtronic (FTC) 26.50p -5.36%Phoenix IT Group (PNX) 235.00p -5.24%Timeweave (TMW) 23.50p -5.05%Sepura (SEPU) 41.00p -4.65%Axis-Shield (ASD) 250.00p -4.58%Emblaze (BLZ) 33.50p -4.29%ProStrakan (PSK) 67.50p -3.91%