Trading on the FTSE commenced 100 minutes late Aug. 16 after suffering the worst outage in more than eight years due to a "trading services issue."
This marked the second trading delay in 14 months, at a time when other European markets were trading higher in early morning trading on Aug. 16.
The London Stock Exchange said earlier in the day it was "investigating a potential trading services issue," causing a delayed open for the FTSE 100 and 250 indexes.
The FTSE 100, which tumbled 1.1% yesterday, was up 0.8% around 9:43 a.m. in London. The Euronext 100 index, Germany's DAX and French stocks were all up around 1% each.
The last time the FTSE faced a major trading delay was in June 2018, when it opened at 9 a.m. London time due to a software glitch, Bloomberg News reported. In February 2011, LSE trading was suspended for a little more than four hours, The Daily Telegraph reported.