Most of the European markets rose Wednesday amid optimism among investors that the European Central Bank would announce bold stimulus measures to rejuvenate the economy and regain growth momentum.

The German DAX 30 index was up 0.18 percent or 12.03 points to 6784.29. Shares of Siemens AG rose 0.94 percent and those of Bayer AG advanced 0.69 percent.

The French CAC 40 index rose 0.51 percent or 16.84 points to 3308.50. Shares of GDF Suez advanced 0.99 percent and shares of BNP Paribas SA climbed 0.71 percent.

London's FTSE 100 index was up 0.33 percent or 18.53 points to 5653.81. Shares of Aggreko PLC rose 1.81 percent and those of CRH PLC were up 1.21 percent.

Spain's IBEX 35 was marginally down 0.08 percent or 5.70 points to 6732.40. Shares of Bankia SA dropped 4.76 percent and those of Bankinter SA fell 1.37 percent.

Market players are hoping for an announcement of the stimulus measures by the ECB as investors feel that bold measures, including easing in the monetary policy, will give a much-needed thrust to boost liquidity in the European financial system.

Investors are anticipating proposals, including bond buying, a rate cut and a new long-term refinancing operation (LTRO), from the ECB for solving the liquidity crisis.  The ECB is expected to be in favor of giving the European Stability Mechanism (ESM) a banking license in the longer term.

Expectations have been increasing ever since ECB President Mario Draghi said last week that the central bank was ready to do whatever it took to preserve the euro. "What is certain is that Draghi has fuelled significant expectations for monetary easing on Thursday, setting a high bar. If expectations are not met, the market reaction will be violent and his credibility will be seriously impaired," Standard Chartered said in a note.