Sweeping Republican party wins in U.S. mid-term elections pushed the dollar to a seven-year high against the yen on Wednesday. More soft data from China left oil at its lowest in four years.

Republicans rode a wave of voter discontent to secure control of the U.S. Senate and strengthen their grip on the House of Representatives in a punishing blow to President Barack Obama that will limit his power in his last two years in office.

Financial markets saw the election results as a cause for optimism. Similar situations in the past have often sparked U.S. stock market rallies.

Futures prices pointed to a 0.5 percent gain for Wall Street when trading opens, while the dollar reached as high as 114.59 yen, its highest since December 2007.

"We all saw this result coming, but the main thing is what the two sides decide, whether they want to co-operate and compromise or whether they are going to go back to the trenches," said Philip Marey, a U.S.-focused economist at Rabobank.

"They (Republicans) have the incentive to be constructive to show to voters that they can rule the country ... If they manage to cooperate it could boost the economy, especially if things can be done on areas like infrastructure."

Growth in China's services sector weakened further in October as new business cooled, reinforcing signs of a gradual economic slowdown that could prod the government to unveil fresh stimulus measures.

In the eurozone, business growth picked up less than expected despite much deeper price cutting by companies. Retail sales were also weak and even high-flying neighbor Britain saw its dominant services sector slow.

The Chinese data was the latest blow for commodities. Brent oil fell towards $80 a barrel as demand worries mounted.