LONDON -- After closing in the red last night, the Dow Jones Industrial Average (INDEX: ^DJI) and S&P 500 are expected to open with a slight increase today. New economic data is expected to show a slight fall in jobless claims in April, while the Philly Fed index is expected to show a pickup in manufacturing activity.

In Europe, uncertainty over the risk of a Greek default and the wider implications it would have for the eurozone are continuing to cause upset, with most major markets trading lower today.

The FTSE 100 (INDEX: ^FTSE) finished the morning down by more than 1%, while Spain's IBEX 35 fared much worse and dropped nearly 2% as shares of part-nationalized bank Bankia crashed on fears of an impending bank run. In this morning's European bond auctions, yields on Spanish government debt due to mature in four years rose to 5.106%, compared with 3.374% seen in March.

In company news, shares in Sears Holdings may rise when markets open, as the company announced an unexpected return to profits in its most recent results, published earlier this morning.

Elsewhere, Facebook is expected to confirm its IPO pricing later today, while retail giant Wal-Mart (NYSE: WMT) is expected to report a 6% rise in both earnings and revenues. Quarterly earnings are also due from Gap and Ross Stores.

Notable in London trading was U.K. and U.S. energy company National Grid (NYSE: NGG), whose full-year results revealed that profits before tax rose by 5% to 2.6 billion pounds. The company also proposed an 8% dividend increase for 2011-2012. National Grid's shares ended the morning up slightly in London, so its ADRs could see above-average activity when markets open.

British banks fell heavily this morning, with Barclays (NYSE: BCS), Royal Bank of Scotland, and Lloyds Banking Group all losing more than 3% of their value. However, the leading British blue chip in which billionaire investor Warren Buffett has invested more than $1 billion was not a bank. Buffett recently bought a famous British name with global expansion potential -- and you can discover the identity of the company and the price he paid in this special free report.

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