Stock markets in Europe and the U.S. rose Monday amid hopes for some big corporate deals, but investors remained wary of deepening troubles in Ukraine and financial indicators due later in the week.

Shares in London-based pharmaceutical company AstraZeneca soared 15 percent after rival Pfizer said it was still interested in buying the company out for as much as $100 billion. In Paris, traders were eyeing high-level talks on the future of Alstom, an engineering conglomerate sought out by General Electric and Siemens.

A man stands await crossing a street outside a securities firm in Tokyo, Monday, April 28, 2014. Shares fell Monday in Asia as investors remained wary of mounting violence in Ukraine. (AP Photo/Junji Kurokawa)

By midafternoon in Europe, Britain's FTSE 100 was up 0.2 percent to 6,701.33, while Germany's DAX climbed 0.4 percent to 9,440.46. France's CAC added 0.3 percent to 4,456.05. Shares in Alstom have been suspended since last week, when they spiked on news of GE's interest.

U.S. shares also rose, with the Dow Jones industrials average up 0.8 percent at 16,485.94 and the S&P rising 0.7 percent to 1,875.54.

Sentiment was held in check by concern over developments in Ukraine. The U.S. and European Union on Monday broadened their sanctions against Russia for its meddling in Ukraine. The U.S. sanctioned seven Russian government officials and 17 companies while the EU added travel bans and asset friezes on another 15 officials, bringing its total to 48.

The U.S. and EU say Moscow has failed to uphold terms of an agreement that calls for it to withdraw Russian forces from the border with Ukraine and encourage pro-Russian separatists to turn over buildings they're occupying in eastern Ukraine.

Meanwhile, pro-Russian militants turned to kidnapping, taking dozens hostage, including journalists, pro-Ukraine activists and European military observers.

Adding to the geopolitical uncertainties is a slew of end-of-month data due this week from Japan, the U.S. and China.

Oil gained 22 cents to $100.82 in electronic trading on the New York Mercantile Exchange amid concern about the potential impact of additional sanctions on Russia's energy exports.

Earlier, in Asia, markets had been weaker. Japan's benchmark Nikkei 225 stock index fell 1 percent to 14,288.23, while Hong Kong's Hang Seng Index lost 0.4 percent at 22,132.53, and South Korea's Kospi gave up early gains to edge 0.1 percent lower to 1,969.26.

Shares in New Zealand, China, India and Singapore fell, while shares rose in Taiwan and Australia.

In other markets, the euro was trading 0.1 percent higher at $1.3853, while the dollar was 0.4 percent higher against the Japanese yen, at 102.58 yen.