The group said Proquote, which it has owned since 2003, “was not central to its strategy going forward for the enlarged Information Services Division”.
The Australian firm said the move was part of its strategy to increase its presence in UK markets.
Proquote operates a trading hub for retail traders in the UK, along with market data terminals.
IRESS’ acquisition also includes LSEHub, which provides trade order connectivity between institutional investors and brokers.
The terms of the transaction were not disclosed but all management and employees are expected to join IRESS.