McNamara will now head the national team in a part-time capacity, and combine the two roles, working under former Catalan coach Trent Robinson at the NRL champions.
He said: “I would like to thank the RFL Board of Directors for giving me this opportunity to carry on working with an outstanding group of players who I firmly believe are on the verge of achieving sustained success.
“I have a great team around me within the England camp and the RFL Performance Department and I will be maintaining regular contact with them all, as well as all the Elite Training Squad players, following my move to Australia.
“I am going to miss rubbing shoulders with the fantastic RFL staff that I have been privileged to work with over the last four years: I’m indebted to them for their friendship and support.
“I have a great relationship with Trent Robinson and am looking forward to working alongside him and the rest of the Roosters staff in what is a very exciting chapter in my career.”
RFL Chief Executive Nigel Wood said: “It gives me great pleasure to confirm that Steve has agreed to continue as England coach into 2014 when we will be looking to build on the advances seen over the last four years.
“We have made considerable progress internationally over the past four years and this arrangement provides stability and continuity.