"Oslo Børs members can now benefit from the high performance and rich functionality of Millennium Exchange, alongside other European users," Tony Weeresinghe, chief executive of MillenniumIT and director of global development at LSE group said in a statement.
"This is an important milestone for London Stock Exchange Group since the Oslo Børs markets were the last still using the legacy TradElect system, which will now be decommissioned."
Oslo Børs, said it was in the process of acquiring Nordic MTF Burgundy, a regional exchange and was planning to use MillenniumIT technology in it next year.
"It is important for Oslo Børs to offer high quality state-of-the-art technology to ensure that our marketplaces remain competitive and to help our customers to offer even better products and services..," Bente A. Landsnes, president and chief executive of Oslo Børs said.
MillenniumIT systems are live in over 30 locations around the World.