Sterling extended losses Friday owing to renewed Brexit uncertainty after Boris Johnson proposed a general election to resolve the long-running saga, while Asian markets were mixed after a broadly positive week.

The pound firmed against the dollar and euro on Wednesday as the European Union prepared to grant a further delay to Brexit, averting the prospect of Britain departing the bloc next week without a deal.

Asian markets rose Tuesday on growing optimism that China and the US will sign a partial trade deal next month, while the pound held firm around five-month highs as dealers bet Britain will leave the EU with a Brexit agreement.

US consulting firm McKinsey said Monday that a third of big global banks may not survive a major financial shock, with those in western Europe and Asia most at risk.

Sterling steadied around $1.29 Friday as dealers paused for breath at the end of a dizzying week and on the eve of a vital vote on Prime Minister Boris Johnson's Brexit deal.

Banks aiding a stock market float for Saudi oil giant Aramco will be "devoid of all sincerity" regarding environmental and social concerns, green and rights groups jointly said Thursday.

Germany on Thursday slashed its growth outlook for next year, saying it expects trade conflicts, Brexit and other sources of uncertainty abroad to continue weighing on an economy that remains buttressed by domestic strength.

China said Thursday that its negotiators have "accelerated efforts" to hammer out the details of a partial deal with the United States, as the two sides edge towards an agreement in a lingering trade war.

Sterling tumbled Thursday after Prime Minister Boris Johnson's key ally in parliament said it "could not support" his plans for a Brexit deal, throwing a spanner in the works just as Britain and the European Union were closing in on an agreement.

The pope on Wednesday contrasted the world's 820 million hungry people with those who turn food into "an avenue of personal destruction" through overeating, in comments to mark World Food Day.