The pan-European Dow Jones Stoxx 600 index (ST:SXXP: news , chart , profile ) rose 1.1% to 195.76.

Of regional indexes, the French CAC-40 index (FR:1804546: news , chart , profile ) rose 1.6% to 3,098.37, the German DAX 30 index (DX:1876534: news , chart , profile ) rose 1.2% to 4,662.85 and the U.K. FTSE 100 index (UK:UKX: news , chart , profile ) rose 1.2% to 4,144.15.

U.S stock futures were also higher, with Dow Jones Industrial Average futures up 93 points. Stocks closed well off early lows on Tuesday after consumer confidence and house-price data were released. Read more on U.S. shares.

Equity markets have rallied since March on hopes that the global economy is stabilizing.

Data out Wednesday in Europe offered more support for this view. The European Commission's economic-sentiment indicator for the 16-nation euro zone rebounded to 67.2 in April from a record low of 64.7 in March, marking the first rise since May 2007.

Additionally, worries about a flu pandemic sparked by deaths in Mexico and the spread of the virus to other countries seemed to abate on Wednesday, with airlines up and shares of flu-vaccine maker Roche (CH:ROG: news , chart , profile ) down 1.4%. Read more on British Airways.

"Investors have shrugged off the uncertainty surrounding the economic impact of the swine flu for the moment," noted Edward Keeling at Dolmen Securities.

Earnings were a main focus on Wednesday in Europe, with Siemens (DE:SIE: news , chart , profile ) shares up 5.6%.

The industrial giant said that its fiscal second-quarter net profit jumped to 1.01 billion euros ($1.33 billion) from 412 million euros a year earlier, exceeding analyst expectations for a 971 million-euro profit.

For the fiscal year the group said it expects operating profit to exceed the 6.6 billion euros it reported in the previous year. Siemens had previously been targeting operating profit of 8 billion euros to 8.5 billion euros for the year. See full story.

Shares of French drug maker Sanofi-Aventis (FR:SAN: news , chart , profile ) rose 3.1%. First-quarter net income rose to 2.18 billion euros, from 1.88 billion euros in the same period a year ago, also topping analyst forecasts. The firm also confirmed 2009 guidance. Read more on Sanofi-Aventis earnings.

Shares of oil giant Royal Dutch Shell (UK:RDSA: news , chart , profile ) climbed 0.3%. The firm reported that its first-quarter net income fell 62% to $3.49 billion.

Stripping out $337 million of one-time gains as well as the price changes on unsold inventories, and Shell's earnings would have been $2.96 billion, better than analyst estimates for a profit of $2.55 billion. See full story.

Shares of Spanish banking giant Santander (ES:SAN: news , chart , profile ) rose 5%.

Its first-quarter net profit also beat expectations, falling 5% to 2.10 billion euros, as increased lending income offset higher loan-loss provisions that were needed to counter the impact of the economic downturn. Read more on Santander results.

Shares in ArcelorMittal (NL:MT: news , chart , profile ) , the world's largest maker of steel, fell 3.8%.

It swung to a $1.06 billion first-quarter loss after earning $2.37 billion in the year-earlier quarter. Still, it sees a potential for price increases during the second and third quarters across major markets and products. See full story.

Other companies losing ground included software firm SAP (DE:SAP: news , chart , profile ) , down 2.4%.

Its first-quarter net profit fell 16% to 204 million euros after it took a restructuring charge of 160 million euros. The profit figure missed analyst forecasts for net income of 261 million euros. See full story.

Shares of German drug maker Bayer (DE:BAY: news , chart , profile ) fell 3.6%. Its first-quarter net income fell 44.2% to 425 million euros, also below analyst forecasts.

"While CropScience and Pharmaceuticals continued on a path of growth, the slump in business at MaterialScience left a distinct mark on sales and earnings," said Cairman Werner Wenning.

Bayer also said that its goal of limiting a decline in adjusted earnings before interest, taxes, depreciation and amortization for 2009 is looking increasingly demanding. Read more on Bayer earnings.

Europe Markets: Shares in Europe rise, led by Siemens, Santander