London's FTSE 100 shares index rebounded when it finally opened on Friday after a delay caused by an unspecified trading issue.
The benchmark index jumped 0.7% to 7 113.44 points when it finally opened at 0840 GMT, 100 minutes after its expected start.
Eurozone stock markets also recovered Friday, with Frankfurt's DAX 30 up 1.1% to 11 534.66 points as the FTSE opened, while the Paris CAC 40 was showing a gain of 0.9% at 5 285.73.
The London Stock Exchange Group said it had been "investigating a potential trading services issue" that prevented the FTSE 100 and second-tier FTSE 250 indices from opening on time at 09:00.
The FTSE 250 gained 0.4% when it finally began trading at 10:35.
Such events are rare, with the last such delayed start in June last year, when the FTSE opened one hour late owing to a glitch.
World stock markets have endured another volatile week as US-Chian trade talk hopes fade and following economic data that pointed to a possible global recession.