Popular protests have toppled entrenched leaders in Egypt and Tunisia, but a defiant Muammar Gaddafi, the world's second-longest-serving leader after the Sultan of Brunei, said he would not be forced out by the deadly unrest sweeping Africa's third-largest oil producer.

European futures signalled a lower open on Wednesday after Wall Street suffered declines on turmoil in Libya.

"Dow Jones was down a lot and Gaddafi refuses to leave," a trader in Zurich said.

"(There were) also very weak figures on the housing market in the USA."

The franc, which investors tend to seek during times of uncertainty, rose to its strongest since Feb. 2 against the dollar and was trading up 0.2 percent at 0.9358.

Against the euro the Swissie dipped, however, after European Central Bank officials stressed their readiness to raise interest rates to fight inflation.

The franc was down 0.3 percent against the euro compared to the New York close, trading at 1.2846.

The franc rose some 15 percent against the euro last year on concerns about southern European sovereign debts and hit a historic high of 1.24 per euro in late December.

Luxembourg's Yves Mersch and Nout Wellink of the Netherlands said on Tuesday the ECB was ready to fight inflation by increasing interest rates when needed, prompting interest rate futures to bring forward expectations for a 25 basis point rate hike to the ECB's Aug. 4 meeting.