The pound recovered against both the dollar and the euro, a day after the UK government narrowly survived a no-confidence vote.
Key European markets were around half a percent lower at the close, while the Dow Jones index was slightly softer in the late New York morning following disappointing results from Morgan Stanley and as the market showed signs of fatigue after a strong run.
Briefing.com analyst Patrick O'Hare said stocks were "overbought on a short-term basis and due for a period of consolidation".
But the broader S&P index and the tech-heavy Nasdaq both showed small gains.
In Europe, meanwhile, "political and economic risks weigh on sentiment," said David Madden, analyst at CMC Markets UK.
British Prime Minister Theresa May scrambled to put together a new Brexit strategy on Thursday with cross-party talks after MPs sparked political turmoil by rejecting her previous agreement with the EU.
May reached out to rival parties shortly after surviving a no-confidence vote Wednesday, hoping to hammer out a Brexit fix that she could present to parliament next week.
- Huawei weighs -
Meanwhile after a tumultuous December for markets, global equities have enjoyed a broadly strong start to the year, largely thanks to optimism China and the US will resolve their trade row.
But confidence took a knock Wednesday from a report that said US officials were carrying out a criminal probe into Chinese tech giant Huawei and could soon indict the firm over allegations of theft of trade secrets from its American business partners.
Lawmakers have also introduced a bill to ban the export of American parts and components to Chinese telecom companies that are in violation of US export control or sanctions laws -- with Huawei and fellow Chinese firm ZTE the likely targets.
"Huawei is effectively an intelligence-gathering arm of the Chinese Communist Party whose founder and CEO was an engineer for the People's Liberation Army," said Republican Senator Tom Cotton, one of the bill's sponsors.
The developments follow the arrest last year in Canada of Huawei's chief financial officer Meng Wanzhou, who is the daughter of the company's founder. She faces extradition to the US on Iran sanctions-linked fraud charges.
It also muddies the waters in trade talks between Beijing and Washington, which looked to be on a positive course after officials held three days of talks earlier this month, with both sides seemingly upbeat.
There are, meanwhile, deepening worries about the impact of the US government shutdown as it moves towards a fifth week, with Oxford Economics estimating it is slashing growth by $700 million a week.