European and US stocks rebounded on Friday after a week in which enthusiasm waned as traders digested worries over the fast-spreading COVID-19 Delta variant, the Federal Reserve's taper plans and China's regulatory crackdown.

Asian markets continued to fall, however, with Hong Kong's main index down 5.8 per cent for the week.

Oil prices fell further on concerns the Delta surge could lead to further closures and restrictions that dampen energy demand.

"We can't ignore the fact that this week has seen a bit of a shift in sentiment when it comes to optimism about the overall recovery story," said Michael Hewson, chief market analyst at CMC Markets UK.

On Wall Street, all major indices ended with gains of less than one per cent, but were lower for the week.

Sentiment suffered after indications from the Federal Reserve it would begin to taper its stimulus this year, while investors have generally been on edge over unrest in Afghanistan and China's regulatory crackdown.

London stocks rose 0.4 per cent amid news UK supermarket Morrisons accepted a £7.0 billion ($9.6 billion, 8.2 billion euro) takeover from US private equity firm Clayton, Dubilier & Rice. 

The FTSE 100 shed 1.8 per cent for the week.

Frankfurt added 0.3 per cent on Friday, but gave up 1.1 per cent over the week.

Paris, which rose 0.3 per cent on Friday, finished the week 3.9 per cent lower.

'Fragile' sentiment 

"Sentiment remains fragile for the moment, and with lighter trading volumes during August, more market volatility is extremely possible," said Richard Hunter, head of markets at Interactive Investor.

A speech by Fed boss Jerome Powell at next week's central banking conference at Jackson Hole, Wyoming, will be keenly watched for details on a timetable for tapering the central bank's massive bond buying program.

AJ Bell analyst Danni Hewson predicted the Jackson Hole event -- which will be held virtually given COVID concerns at the retreat -- would give "central bankers and other economic decision-makers a chance to outline their plans for the next phase of the pandemic recovery."

Colossal government and central bank support as well as optimism that vaccine rollouts would enable economies to recover from the pandemic have sent share prices surging over the past year.

However, the latest virus mutation has forced experts to rethink their outlooks for growth as some countries reimpose containment measures and infection rates rise.

Hong Kong's main index closed nearly two per cent lower in Friday trading following Beijing's passage of a sweeping privacy law to prevent state and private firms from collecting sensitive information on people. 

The move comes after leaders clamped down on a range of industries -- particularly tech giants -- citing personal data issues as well as security and antitrust breaches.

Key figures around 2050 GMT

Dow: UP 0.7 percent at 35,120.08 (close)

New York - S&P 500: UP 0.8 percent at 4,441.67 (close)

New York - Nasdaq: UP 1.2 percent at 14,714.66 (close)

London - FTSE 100: UP 0.4 percent at 7,087.90 (close)

Frankfurt - DAX 30: UP 0.3 percent at 15,808.04 (close)

Paris - CAC 40: UP 0.3 percent at 6,626.11 (close)

EURO STOXX 50: UP 0.6 percent at 4,147.50 (close)

Tokyo - Nikkei 225: DOWN 1.0 percent at 27,013.25 (close)

Hong Kong - Hang Seng Index: DOWN 1.8 percent at 24,849.72 (close)

Shanghai - Composite: DOWN 1.1 percent at 3,427.33 (close)

Euro/dollar: UP at $1.1705 from $1.1675 

Pound/dollar: DOWN at $1.3626 from $1.3639

Euro/pound: UP at 85.87 pence from 85.60 pence

Dollar/yen: UP at 109.80 yen from 109.74 yen

West Texas Intermediate: DOWN 2.2 percent at $62.32 per barrel

Brent North Sea crude: DOWN 1.9 percent at $65.18 per barrel