London Stock Exchange Sued by Analytics Firm Founder for Fraud

London Stock Exchange Group Plc defrauded MayStreet Inc.'s corporate leaders into accepting a deferred-payments deal structure when the financial markets giant bought the analytics firm, according to an unsealed lawsuit.

Maystreet founder Patrick Flannery is suing LSEG over the 2022 acquisition, saying the operator of Europe’s largest capital market based the transaction on promises it never meant to keep. LSEG knew post-deal payments were pegged to milestones the business couldn’t hit, according to the partly redacted court complaint made public Thursday. The filing blacks out the sale price, which wasn’t publicly announced, and most other dollar figures.

The allegations reflect ...