The much sought after former Rugby League playing great had shared his time between English Premiership club London Wasps and Wales prior to the new agreement reached with chief executive Roger Lewis in 2011 which made the WRU his primary employer and has seen him extend his role to the Wales National Academy sides and coach at U20s, U18 and U16 level when he is not on national duty.
However, the agreement reached also allowed a period of time for Edwards to keep his coaching ambitions alive in the English Premiership, hence the endorsement of this new part time role with London Irish.
"Shaun is always going to be a coach in demand and this new arrangement with London Irish will be of mutual benefit to all concerned," said a WRU spokesperson.
"It will keep Shaun at the very cutting edge of the game at a domestic level, as did his prior arrangement with London Wasps and that can only of benefit to Wales.
"Shaun's appointment alongside Warren Gatland and Rob Howley to the Wales national squad coaching staff coincided with the 2008 RBS 6 Nations Grand Slam and the same coaching unit went on to take charge of the British and Irish Lions' tour of South Africa in 2009, under Sir Ian McGeechan.
"The unit took Wales all the way to the RWC semi-finals in 2011 before repeating their '08 efforts with another clean sweep in 2012.
"We have been more than pleased to be able to negotiate terms with all of our current coaching staff to keep them in place until at least the culmination of the 2015 World Cup and are just as pleased to wish Shaun well with his new role at London Irish.
"Shaun has already done some great work with the Wales U20 and Wales U18 teams and he is determined to continue with this activity within his WRU duties going forward."