LONDON: Investors hit the pause button on Wednesday as they awaited this week's key Jackson Hole symposium of central bankers, with particular focus on Fed chief Jerome Powell.

In Europe, London stocks advanced 0.3 percent, while Paris added 0.2 percent and Frankfurt sagged 0.2 percent in afternoon trading.

Wall Street drifted higher at the open, with both the S&P 500 and Nasdaq Composite rising from record closes.

Oil prices made modest gains after jumping more than eight percent in the previous two days on hopes for a demand rebound.

"Traders are largely sitting on their hands today after bidding up prices of stocks, crude oil and other risk assets in the first two days of the week," said ThinkMarkets analyst Fawad Razaqzada.

"There hasn't been much in the way of fresh catalysts to provide direction, with all the attention being on Friday's speech by Jerome Powell."

Powell's upcoming speech to the virtual gathering of economists will be examined for clues on the Fed's plans for monetary policy -- with an eye on the Delta Covid variant's impact on growth.

Asian markets were also mixed, with news that US President Joe Biden's multi-trillion-dollar spending plans were edging closer providing another colossal boost, but the optimism was offset by profit-taking after a strong start to the week.

"The lackluster disposition is not altogether surprising," said market analyst Patrick O'Hare at Briefing.com, as some believe profit-taking will resume while others that the rebound has nearly run its course.

"What can't be overlooked, however, is that there still isn't any concerted selling interest," he said.

"That's a testament to the underlying bullish bias that keeps shining through on interim bouts of weakness."

Global markets had jumped Monday on bargain-hunting after last week's retreat, with traders riding a wave of renewed optimism.

Stocks were battered last week by worries over the fast-spreading Delta variant, Afghanistan turmoil, China concerns, and expectations that the Fed will begin tapering financial support.

However, the US Food and Drug Administration's decision on Monday to give full approval to Pfizer-BioNTech's vaccine has also given a huge lift to sentiment and eased Delta worries in the world's top economy.

That came as some countries including the United States see infection spikes easing, while China appears to have overcome a weeks-long outbreak. Still, others such as Australia, Japan, and New Zealand remain in a tough battle with the disease, forcing them into containment measures.

The FDA move "is paving the way for organisations to mandate vaccines for workers and thus lift vaccination rates higher", said National Australia Bank's Tapas Strickland.

Wall Street enjoyed another strong day on Tuesday, with the S&P 500 at a record and the Nasdaq topping 15,000 for the first time.

Buying was helped by news that Democrats in the House of Representatives had settled internal differences to push forward Biden's massive spending bill.