European markets close higher ahead of key Fed speech; Elekta shares jump 11%

• The pan-European Stoxx 600 index provisionally closed up by 0.8%, reversing earlier losses, with almost all sectors and major bourses in positive territory.
• Market sentiment was helped in part by data that showed U.S. durable goods orders surging 11.2% in July, easily beating estimates.
• Investors are looking ahead to the Federal Reserve's annual symposium on monetary policy Thursday, to be held in a virtual format this year.

European stocks closed higher on Wednesday, amid optimism about U.S.-China trade and ahead of a key speech by the U.S. Federal Reserve chairman.

European markets

The pan-European Stoxx 600 index provisionally closed up by 0.8%, reversing earlier losses, with almost all sectors and major bourses in positive territory.

Technology shares led the gains with a 2% rise. Aveva was the top performer in the sector, climbing almost 10% after announcing a $5 billion deal to buy SoftBank-backed U.S. software firm OSIsoft.

Europe's early market moves follow relatively lackluster trade in Asia on Wednesday. Asia Pacific stocks were lower in afternoon trade despite major indexes on Wall Street notching up new records yet again Tuesday.

U.S. markets were bolstered by China and the U.S. resuming trade talks in the previous session. In a statement, the Office of the U.S. Trade Representative said that both sides made progress and were "committed to taking the steps necessary" to ensure the success of the phase one trade deal. 

On Wednesday, U.S. stocks mostly rose with the S&P 500 and Nasdaq indexes in positive territory, however, the Dow Jones Industrial Average was slightly lower.

Market sentiment was helped in part by data that showed U.S. durable goods orders surging 11.2% in July, easily beating estimates.

Powell speech

Investors are looking ahead to the Federal Reserve's annual symposium on monetary policy Thursday, to be held in a virtual format this year. Wall Street will look for clues on further stimulus and where the economy is headed out of the event. Investors will be looking specifically for Fed Chairman Jerome Powell's comments on inflation and its impact on the dollar.

Back in Europe, Sweden's Elekta surged to the top of the European benchmark on Wednesday. Shares of the Stockholm-listed firm rose 11% after the radiation equipment maker reported a big jump in profit through the company's first quarter.

Meanwhile, Denmark's Ambu slumped to the bottom of the Stoxx 600. It comes after the company, which makes diagnostic and life-supporting devices, downgraded its forecast for organic growth for the 2019/2020 financial year. Shares of the Copenhagen-listed company fell more than 13% on the news.

— CNBC.com staff contributed to this market report.