Banking and asset management giant Investec has exited the FTSE 100 as part of the latest re-shuffle of the UK's leading share index.
Economic growth in the UK will be subdued and output will fail to reach 2008 levels until 2013, according to the National Institute for Economic and Social Research (NIESR).
The FTSE 100 is down 1.2% and US markets have also opened lower as investors' hopes for a positive outcome from Friday's EU summit begin to dwindle.
Goldman Sachs Asset Management chairman Jim O'Neill said BRIC investors are on tenterhooks waiting for this week's EU summit, as progress on solving the debt crisis will boost appetite for eurozone debt.
Chancellor George Osborne has announced the 2012 Budget will be held on Wednesday 21 March.
Brazil's economic growth slowed in the third quarter of 2011 as the impact of the crisis in Europe and the slowdown in global growth impacted the region.
Today's oil price is a risk to global economic growth, particularly in the US, said BP chief executive Bob Dudley.
Asian markets rallied overnight as Moody's mulled raising the ratings of some Asian countries, while investors pinned their hopes on an EU summit to solve the debt crisis.
UK Prime Minister David Cameron has threatened to veto plans for an overhaul to the EU treaty on grounds it could damage British interests.
The Treasury wants to force the highest paid staff at 15 of the UK's largest banks to publicly disclose their pay.