Employees walk past FTSE AIM share price information displayed on an illuminated rotating cube at the atrium of the London Stock Exchange Group offices in London, U.K.

London's FTSE 100 index opened higher on Friday after a nearly two-hour delay in trading due to a technical glitch.

The index was up 0.8% in early market trade, adding to gains to the overall European stock markets that traded higher in the morning session.

The London Stock Exchange (LSE) had earlier confirmed to CNBC that there were problems with trading.

"Can confirm there are technical problems affecting certain securities on the London Stock Exchange," a spokesperson from the LSE told CNBC Friday.

"Investors would have been yearning for a quiet Friday after a week of turmoil for the markets driven by recession fears," AJ Bell investment director Russ Mould said in a statement.

"And it looked like just such a peaceful interlude was on the cards until technical issues at the London Stock Exchange delayed the start of trading in FTSE 350 stocks, delaying an expected rebound for the index," he added.

FTSE 100, U.K.'s blue-chip index, hit a six-month low on Thursday as an escalating trade war between the United States and China and growing concerns about the world economy saw global stocks in sell-off mode.

The index is down more than 6.7 percent over a 30-day period but is still up more than 5 percent since the start of the year.

The Financial Times Stock Exchange 100 index, or also called the FTSE 100 index, includes the 100 LSE-listed companies listed with the highest market capitalization. The total market cap of FTSE 100 index is £1.89 trillion ($2.28 trillion) — more than double the market cap of Apple.