Frankfurt's DAX 30 advanced 0.78 percent to 9,139.00 points and in Paris the CAC 40 gained 0.35 percent to stand at 4,126.97 compared with Tuesday's closing value.
In Paris, shares in drugmaking group Sanofi fell by 5.38 percent to 70.72 euros after the removal of the group's chief executive. The shares had fallen by more than 10.0 percent on Tuesday on a results setback and speculation that the top executive would be pushed out.
Shares in micro-processor maker STMicroeletronics plunged 7.09 percent to 5.17 euros after the group warned that activity would slow down in the fourth quarter of this year.