Munro has ditched Test cricket for his passion for the purest form of cricket has diminished.
Despite holding a first-class average of 51.58, he has also ruled himself out of New Zealand's domestic four-day competition for the remainder of the season.
The 30-year-old has played his only Test for New Zealand in 2013 against South Africa.
"It would be fair to say that my focus hasn't been on four-day cricket this season and my passion for that format of the game isn't what it once was," ESPNcricinfo quoted Munro as saying.
However, he will continue to play the One Days and Twenty20 cricket at both domestic and international level.
"I'm still 100% committed to playing for the Blackcaps and Auckland Aces in the shorter formats and have some big goals I'd like to achieve in the next couple of years," he said.
Munro, the world's top-ranked batsman in Twenty20 cricket, has struck three hundred in the shortest format of cricket, the most by any player.
"Obviously with the World Cup next year I'd love to give myself the best chance of making that squad and that's where my main focus is," the southpaw batsman said.