Peter Dixon, senior economist at Commerzbank Securities, shares his views on the disappointing U.S. GDP numbers.

European shares extended losses to close lower on Wednesday after U.S. gross domestic product data came in weaker than expected.

Zafar Khan, aerospace analyst at Societe Generale, tells CNBC that Boeing's Dreamliner battery problems will cause long term uncertainty in the market, although in the short term they won't be too badly affected.

James Ferguson, founding partner of Macro Strategy Partners, tells CNBC why he thinks the Fed have over-stimulated the US economy through too much quantitative easing.

William Connors, reporter at the Wall Street Journal, tells CNBC that RIMM's biggest challenge will be marketing their new BB10 to a wide enough audience to make the necessary impact.

Juergen Pieper, co-head of research at Bankhaus Metzler, tells CNBC why the European car market outlook is not as pessimistic as has been made out, although it should be braced for a tough start to 2013.

Sarah Perez-Frutos, partner at Dracon Partners, tells CNBC that Spain desperately needs stimulus measures if its economy is to reverse a sharp decline.

Fernando Fernandez from the IE Business School, tells CNBC that the Spanish data has to be put in perspective and is not really that bad considering the amount of fiscal consolidation.

David Richards, CEO at Wandisco, tells CNBC that the British venture capital industry has too many people from an accounting background and not enough people from a technology background.

Christian Gattiker-Ericsson, global investment strategist at Julius Bär, tells CNBC that they remain constructive on the market and expect it to do well at least until the end of this quarter.

Steve Sedgwick takes you through the European markets which have opened slightly easier.

Majid Jafar, CEO of Crescent Petroleum, tells CNBC that a general sense of instability post the Arab Spring has already been factored in to the oil price but there has been no direct impact from the Algerian hostage attack.

Michael Wolf, CEO of Swedbank, tells CNBC that despite the economy 'biting' they are proud to have adjusted the bank to the new regulatory environment.

Severin Schwan, CEO of Roche, tells CNBC that 2012 was a very good year for Roche with the company outgrowing their markets in both Pharma and Diagnostics by five and four percent.

David Hutchings, head of European research at Cushman and Wakefield, tells CNBC that the commercial property market in Europe rebounded in Q4 driven primarily by foreign investors.

Alberto Perlman, co-founder and CEO of Zumba, talks to CNBC about the business model behind Zumba.

Erich Hauser, automotives analyst at Credit Suisse, explains to CNBC why investors are shorting the European car industry.

Norman Villamin, chief investment officer for Europe at Coutts, says Italy's political risks have diminished as Italians head to the polls in February.

On the S&P 500's 20th birthday, Dodd Kittsley, global head of ETP research at Blackrock, tells CNBC that the index's sheer breadth of investors is the most significant factor behind its success.

Nick von Schirnding, CEO of Bumi, tells CNBC, that Indonesian mining company Bumi is in a 'total mess' and that mess started when Nat Rothschild brought it to London market.