European markets stable at open

London - Europe's main stock markets steadied at the start of trading on Friday in cautious deals before a key speech from US Federal Reserve chief Janet Yellen.

London's benchmark FTSE 100 index rose 0.04% to 6 780.08 points and Frankfurt's DAX 30 gained 0.12% to 9 390.29, while the CAC 40 index in Paris fell 0.04% to 4 291.06 compared with Thursday's closing level.

Later on Friday, Yellen will deliver a keynote speech at the Fed's annual conference in Jackson Hole, Wyoming, as investors continue to speculate on the direction of US interest rates.

European equities had marched higher on Thursday, cheered by hints the Fed could raise interest rates sooner than expected in view of US growth, and despite mixed eurozone data.

"Traders will keep a close eye on Fed chief Janet Yellen who will deliver a speech on labour markets later this afternoon," said analyst Markus Huber at brokerage Peregrine & Black in London.

"Any hints that the labour market is more balanced and healthier than earlier this year might lead to a reassessment by analyst concerning the likely timing of a first rate rise."