* Barrenjoey & JPMorgan offering A$13.20 - source

* Shares surge the most since 2018

* IRESS has not received any direct approach - Co

SYDNEY, June 10 (Reuters) - Shares in Australian trading software company IRESS jumped the most since 2018 on Thursday after investment banks sought to buy a small shareholding in the firm on behalf of an anonymous buyer, sources said.

Shares in IRESS, one of the main providers of trading and investment software to Australian brokerage firms, jumped over 16% after the Australian Financial Review newspaper's Street Talk column said investment bank Barrenjoey had been seeking to buy shares on behalf of a financial sponsor.

Melbourne-based IRESS told the market in a statement that it had been aware of "market activity by an unknown participant or participants", but that it had "not received any direct approach".

A source briefed about the approach told Reuters Barrenjoey and JPMorgan had been sounding the market in previous days to buy shares in the company at about A$13.20, a level it had not reached since February 2020.

Iress shares on Thursday closed 16.8% higher at A$12.79. Barrenjoey and JPMorgan declined to comment. (Reporting by Paulina Duran in Sydney; Editing by Stephen Coates)