The pan-regional STOXX 600 index index lost 0.9pc and was set for its worst day in a week as caution prevailed ahead of UK general election and central bank meetings in the United States and the euro zone.
Germany's trade-sensitive DAX led the decliners among regional peers, while export-reliant miners and auto stocks shed nearly 1pc.
All the major European subsectors were trading lower.
"Expectations (for a US-China trade deal) have been quite high until recently," said Jonathan Bell, Chief Investment Officer at Stanhope Capital.
"There is a greater chance now that there is no real announcement. It's either delayed or such a small agreement that the market isn't going to take it positively."
Signs of progress in Sino-US trade relations were a major catalyst in powering the benchmark index to four-year peaks last month.
However, growing fears about the trade deal getting delayed until the end of 2020 has hurt market sentiment, with the STOXX 600 now about 2pc below those levels.
The next important date in the dispute is Dec. 15, when new US tariffs kick in on Chinese imports.
Meanwhile, in the UK election on Thursday, opinion polls have put the ruling Conservatives on course for a parliamentary majority, enabling Brexit to go ahead by the end of January.
In corporate news, Ashtead Plc slid 7.7pc and was among the biggest drags on the benchmark index.
The equipment rental giant said it plans to refocus its A-Plant business in the UK due to competitive pricing and market uncertainty.
British fashion retailer Ted Baker Plc slumped 17pc to a 16-year low after it announced the departure chief executive and chairman, cut its full-year outlook again and suspended a dividend payout.
French car parts maker Valeo slipped 4.5pc after issuing disappointing mid-term targets.
In a bright spot, Sanofi rose 4.8pc, on track for its best day in three years, after the French drugmaker said it would revamp its business in the hope of bolstering growth and profit.