Britain's FTSE 100 skidded 0.4% to 7,297 in midday trading, while Germany's DAX slipped 0.1% to 12,856. France's CAC 40 edged up 0.1% to 5,692.86. U.S. shares were set for a flat to modest open, with Dow futures inching up slightly to 26,782. S&P 500 futures were up 0.1% at 3,008.
Faltering progress toward the United Kingdom's departure from the EU took another setback when British Prime Minister Boris Johnson said Thursday he plans to ask Parliament to vote Monday on a motion calling a national election for Dec. 12.
That came two days after lawmakers stymied Johnson's latest attempt to get approval for his proposal for leaving the 28-nation bloc. EU officials are meeting Friday in Brussels to decide whether to grant an extension to the Oct. 31 Brexit deadline.
Meanwhile, traders have been bracing for weaker results this earnings season amid concerns about the costly trade war between the U.S. and China, and increased signs of slowing economic growth worldwide.
However, earnings reports so far have mostly exceeded Wall Street analysts' modest expectations. "The past week saw most major share markets push higher helped by generally good U.S. earnings reports, benign geopolitical news and optimism that global recession will be avoided," said Shane Oliver, chief economist at AMP Capital.
In Asian trading, Japan's benchmark Nikkei 225 added 0.2% to finish at 22,799.81. Australia's S&P/ASX 200 gained 0.7% to 6,739.20. South Korea's Kospi edged 0.1% higher to 2,087.89. Hong Kong's Hang Seng dipped 0.4% to 26,683.95, while the Shanghai Composite advanced 0.5% to 2,954.93.
U.S. and Chinese officials have been working on the details of an agreement aimed at resolving some of the disputes that have embroiled the world's two largest economies in a tariff war that is squeezing manufacturers and farmers on both sides.
U.S. Vice President Mike Pence adopted a hard line in a speech Thursday laying out President Donald Trump's China policies. He accused companies, including Nike and the NBA, of being too willing to ignore Chinese censorship and repression in pursuit of profits. He also said the FBI has 1,000 active investigations into intellectual property theft, most of them involving China.
Pressure on U.S. companies to share advanced technology is one of the key sticking points in the dispute with Beijing over its own industrial and trade policies. Pence also reiterated U.S. support for protesters in Hong Kong who have been holding increasingly violent demonstrations for more than four months to voice their fears Beijing is infringing on liberties promised to the semi-autonomous region when China took control of the former British colony in 1997.
So far, American backing for the protesters has drawn sharp rebukes from China but hasn't appeared to affect the trade talks. But the expected approval of a resolution expressing support for the protesters by the U.S. Senate, following a similar one in the House of Representatives, is likely to anger Beijing further.
ENERGY: Benchmark crude oil dipped 9 cents to $56.14 a barrel in electronic trading on the New York Mercantile Exchange. It rose 26 cents to $56.23 a barrel Thursday. Brent crude oil, the international standard, lost 7 cents to $61.60 a barrel.
CURRENCIES: The dollar was little changed, rising to 108.57 Japanese yen from 108.60 yen on Thursday. The euro rose to $1.1111 from $1.1105.
Matt Ott in Washington contributed to this report.