London Stock Exchange suffers 90 minute outage

London(CNN Business) The London Stock Exchange suffered a technical glitch Friday that prevented investors from trading its biggest stocks for more than 90 minutes.

The opening of the FTSE 100 and FTSE 250 indexes was delayed by what the exchange described as a "trading services issue."

While other parts of the market opened as usual, trading in FTSE 100 and FTSE 250 stocks did not begin until 9:40 a.m. in London.

Barclays (BCS), BP (BP), HSBC (HSBC) and Rio Tinto (RIO) are among the companies that make up the FTSE 100.

London's stock market previously suffered a technical glitch in June 2018 that delayed the start of trading by one hour.

The London Stock Exchange (LDNXF) agreed earlier this month to buy financial data provider Refinitiv from a group of investors led by Blackstone (BX).

If completed, the deal would combine the data generated by the exchange with Refinitiv's global distribution and analytics.

It would also bolster the UK company's position in foreign exchange and fixed income trading through Refinitiv's FXall and Tradeweb platforms.

In February, an electronic trading system operated by CME Group (CME) was hit by a three-hour outage caused by a technical issue.