Europe's benchmark stock index advanced on Monday, rebounding after its biggest weekly loss since January, as RWE AG and Vodafone Group PLC rose after deal activity. Meanwhile, investors monitored developments in Ukraine after preliminary results showed a majority of Crimeans voted to join Russia.

The Stoxx Europe 600 index gained 0.7% to 324.35, on track to break a three-day losing run.

Helping lift the benchmark, shares of RWE picked up 1.1% after the German utility firm said it plans to sell its oil- and gas-production unit to Russian billionaire Mikhail Fridman in a transaction valued at more than 5 billion euros ($7 billion).

At the other end of deal making, Vodafone (VOD) put on 1.8% after the U.K. telecoms firm reached an agreement to buy Spanish cable operator Ono SA for just over EUR7 billion, including debt.

In the U.K., home builders posted solid gains after U.K. Chancellor of the Exchequer George Osborne on Sunday said he'd extend the Help-to-Buy scheme until 2020. Shares of Taylor Wimpey PLC gained 3.2%, Crest Nicholson Holdings PLC added 4.2%, and Barratt Developments PLC picked up 3.1%.

Aside from corporate news, the ongoing tensions between Ukraine and Russia kept investors on edge. On Sunday, more than 95% of voters in Ukraine's Crimea region chose to secede from Ukraine and let the peninsula rejoin Russia, according to preliminary results reported in The Wall Street Journal. The referendum was deemed illegal by the Ukrainian government in Kiev, the U.S. and the European Union. The White House on Sunday said the vote goes against Ukraine's constitution and was held under "threats of violence and intimidation from a Russian military intervention that violates international law."

The U.S. and the EU have threatened to impose sanctions on Russia if President Vladimir Putin's government follows through with annexing Crimea. EU foreign ministers are slated to meet in Brussels on Monday and could impose visa bans and freeze assets for some Russian officials, according to Bloomberg.

Russian stocks moved higher in Monday's action, with the MICEX Index up 3.4% to 1,2483.13. The benchmark closed with a loss of more than 7% last week, as tensions rose ahead of the Crimea vote.

Other European benchmarks were also rising after sharp losses last week, with Germany's DAX 30 index up 0.6% at 9,110.99 and France's CAC 40 index 0.7% higher at 4,244.57. The U.K.'s FTSE 100 index added 0.4% to 6,556.31.

In data news in Europe, fresh Eurostat numbers showed the euro zone's annual inflation rate was lower in February than initially estimated. Consumer prices rose 0.7% last month, a downward revision from the 0.8% "flash" reading. The revision means euro-zone inflation has dropped further below the European Central Bank's target of just under 2%, which could add more pressure on the central bank to cut rates or otherwise loosen policy at its April meeting.

ECB President Mario Draghi last week expressed concerns that the strong euro could wreck the region's fragile economy and pull down inflation, signaling a willingness to add stimulus measures to fight off deflationary pressures. The euro (EURUSD) on Monday traded at $1.3893, down from $1.3910 late Friday, but up more than 6% against the dollar over the past 12 months, according to FactSet data.