After opening marginally higher, the STOXX 600 climbed 1pc after Bloomberg reported that the two sides were closer to agreeing on the amount of tariffs that would be rolled back in a "phase one" trade deal.
The report lifted the benchmark from a one-month low hit on Tuesday after US President Donald Trump said the trade deal might have to wait until after the presidential election in November 2020, with a US bill protecting Muslim minority in China's Xinjiang adding to the uncertainty.
"That Bloomberg comment seems to suggest that the two nations can have a political disagreement about what is going on in certain areas on one hand, but that won't necessarily affect how they move forward in terms of the trade negotiations," said Connor Campbell, a financial analyst at Spreadex in London.
"It suggests that a deal can be done by Dec. 15, which is really the key date here, before the imposition of new tariffs."
Adding to the upbeat mood, IHS Markit's final reading on November business activity in the euro zone came in slightly better than expected.
German shares were up 1.1pc, on course to post their biggest percentage gain in a month.
Chipmakers such as Infineon Technologies and STMicroelectronics gained about 2pc after upbeat earnings forecast from US peer Microchip Technology.
Dutch semiconductor company ASML Holding rose 2.6pc after J.P. Morgan raised its price target on expectations of strong performance in 2020.
French shares gained 1.2pc after Trump and President Emmanuel Macron said on Tuesday they hoped they could smooth out their differences over the digital services tax.
Washington has threatened 100pc tariffs on French champagne, handbags and other products due to the tax.
Shares in Airbus rose 2pc after winning an order from US carrier United Airlines.
Shares in Swedish industrials group Trelleborg added 5.5pc after announcing restructuring plans that would move it to three business areas from five.
A big decliner was French telecom company Orange, sliding 4.3pc, after traders pointed to disappointment over the firm's dividend outlook even as it announced plans to carve out its mobile towers in most European countries where it is present. Europe's telecoms index was down 0.5pc.