The agency, which picked up the account after a competitive pitch against undisclosed agencies, will first be tasked with an out-of-home campaign to promote the firm in the City.
The activity will be planned by Maxus and booked through its sister outdoor agency, Kinetic.
The campaign includes taxi media activity, complemented by Underground LCDs and advertising at key commuter rail terminals.
ODL Markets is owned by Forex Capital Markets and includes several financial trading platforms. Trading through the company includes spread betting, futures, options and equities.
The outdoor campaign is the first launched by the client.
Graeme Matthews, account director at Maxus, said: "We are delighted to be working with ODL Markets at an exciting period of growth for them in the UK."
Last week, Maxus promoted Adrian Carpenter to UK investment director, heading up a new structure that aims to get better trading deals for existing and new clients.
Broadcast director Andy Benningfield, press director John Maloney, digital director David Fineman, head of cinema Carl Hillery and head of video-on-demand Ruth Cartwright, will all report to Carpenter as part of the change.
Carpenter reports to the agency’s chief executive, Lindsay Weedon.