UK and other European stock markets built on earlier gains on Friday, after a turbulent week for markets.
Leading European indexes including the FTSE 100 were almost 2% higher at midday.
The improvement followed US shares, which swang into positive ground on Thursday.
This week has been torrid for global markets, which have been unsettled by global political and economic uncertainty.
The 100 share index was up 1.87%, or 122.86 points, at 6,707.54.
Stock markets around the world have swung significantly between gains and losses.
Friday’s European gains come after an Asian trading session that was steadier than in recent days.
Japan’s Nikkei 225 closed down 0.31% at 20,014.77, while Hong Kong’s Hang Seng index closed flat, at 25,504.20.
In Germany and France, the DAX and CAC indices were 1.9% higher.
The price of oil, which has also see-sawed this week, was up 1.5% at $52.94 a barrel.
Overnight, the Dow Jones – which fell by more than 500 points or 1.8% earlier on Thursday – finished 1.1% up.
The S&P 500 and tech-heavy Nasdaq also rallied by the end of the Thursday’s trading day.
The earlier sell-off was sparked by weak US consumer confidence data for December. However, analysts had cautioned that volatile share price movements were exacerbated by thin holiday trading.
Concerns about US-China trade tensions also resurfaced, with reports saying US President Donald Trump is considering an executive order banning the use of Chinese technology.