London shares shake-off early gains to slump badly despite market hopes of a boost from economic policy in China. The benchmark FTSE 100 index tumbles 55 points, or roughly 0.47%, to 7,051 as fears spread across the market about the UK's economic health after weaker than expected GDP growth of just 0.3% in the first quarter. Economists had been anticipating 0.5% growth.

In corporate news, Premier Inn and Costa owner Whitbread (WTB) is down 2% to £53.30 on news chief executive Andy Harrison is to step down by February 2016 after five years in the role. It comes as the group reports an 18.5% increase in underlying profit before tax to £488.1 million for the year to 26 February 2015 with like-for-like sales at Premier Inn and Costa up 9.1% and 6% respectively.

BP (BP.) is the first of the UK's integrated oil companies to report its first quarter results and ticks up 0.8% to 480.7p on a set of numbers which are better than feared as a strong contribution from its refining arm helped mitigate the impact of lower oil prices. BP reported first-quarter underlying replacement cost profit, the company's definition of net income, of $2.58 billion, down nearly 20% from the same period last year but up 15% from the fourth quarter of 2014 and well above analyst expectations of $1.28 billion.

Drinks can maker Rexam (REX) falls 0.8% to 580p after warning the trading environment in 2015 will continue to be tough. Global volumes were up 5% in the first quarter with good growth in energy drinks and growth in Russia, the UK, Germany and Italy offset by weaker performances in the Middle East, North America and South America.

Among the bigger movers, joy among tungsten mining stocks with two notable price movements. W Resources (WRES:AIM) jumps 20.7% to 0.35p as it reports positive exploration results for the Regua project in Portugal. Zimbabwe-based Premier African Resources (PREM:AIM) advances 6% to 2.65p after saying construction is on track for its RHA project. That means the latter's share price is now up 83% since we highlighted the stock's appeal a mere 12 days ago in Shares.

biotech funds are among the heavy losers on Tuesday as disappointing data in the US drags share prices lower. Oxford Biomedica (OXB) and International Biotechnology Trust (IBT) comes under selling pressure, both off around 3% to 4%.

Rose Petroleum (ROSE:AIM) slumps 21% to 0.93p despite revealing core results to date from the Mancos Shale formation, in the Uinta Basin, Utah, reconfirm the area's prospectivity and have provided the positive technical data hoped. Full core analysis was on track for Q2.

InfraStrata (INFA:AIM) slides nearly 12% to 3.75p as it posts half-year losses £599,048, from a loss of £705,952 last time.

Mining microcap ECR Minerals (ECR:AIM) is also in the wars, 9% lower at 0.12p as it issues 60.96 million new shares at 0.108p each to YA Global following the conversion of $100,000 of the convertible loan facility. This leaves a total of US$1,385,712 in principal amount outstanding under the facility.

Pinnacle Technology (PINN:AIM) jumps 20% to 6.75p after conditionally raising £0.86 million gross via a placing of 13.2 million new shares at 6.5p each. The placing is to facilitate a strategic investment by MXC Capital (MXCP:AIM), unchanged at 3p. Investors are no doubt excited by MXC's interest given its management's buy and build credentials.

Talent management software minnow NetDimensions (NETD:AIM) leaps more than 6% 87p as it posts both revenue and invoiced sales for the quarter ending March substantially ahead of the comparative period last year.

Regenerative medicine specialist Tissue Regenix (TRX:AIM) jumps 9% to 18p on the European regulator clearing it to start clinical trials on torn knee ligament treatment Orthopure. This is the first step in accessing a market of 900,000 suffers that is growing at 7% a year.

Italy focused E&P Sound Oil (SOU:AIM) is up 3.7% to 24.5p as it confirms alongside 2014 results that it is in discussions with a 'major oil and gas company' to fund and de-risk some of the assets in its portfolio. Sound finished last year with £12.6 million in cash.

Carpet manufacturer Victoria's (VCP:AIM) magical ride continues, the shares up another 5.3% (42.5p) to 847.5p as a positive pre-close update stokes upgrades. Victoria says profit before tax for the year to March will beat expectations, the new financial year has started well and the sector consolidator has also increased its bank facilities. Shares highlighted Victoria's investment attractions in October.

Mobile gaming group Nektan (NKTN:AIM) edges up 0.9% to 169p after announcing a financing package of £7.1 million, comprising the issue of £4.7 million of convertible loan notes and more than a million shares, to support its US expansion and European growth.

Issue Date: 28 Apr 2015