"This means selling our controlling stake in the club to the right investors who can bring capital and renewed vigour to ensure the Breakers' ongoing success.
Blackwell cited recent games played between Melbourne, Brisbane and Sydney against American NBA clubs, and a strong increase in attendance and television audiences through the opening weeks of the NBL season.
Under the Blackwells' stewardship, the Breakers have operated under a famous "no dickheads" policy which, alongside family barbecues and game-day home baking, have added to the club's folklore.
Breakers general manager Dillon Boucher says the decision is about growing the club's legacy.
"They have built this club to where it is culturally with their community spirit, but they now want someone to come in and focus more on the commercial side more to continue growing the club's sustainability.
"The generosity of their time and energy has been incredible. Nothing symbolises that more than their approach to the imports. They'd meet them at the airport at 5.30am upon arrival, or deliver their 'orphans Christmas' to make sure they felt welcome in a home away from home."
"Everyone who knows our story knows our goals have been community focused," Blackwell added.
"Yes, we have pursued on court success and we have achieved more than we dreamed of, with four championships and five grand final appearances over the past seven years.
"But for us the main goal was to build a club that gives back, one that young New Zealanders can look up to, a club that sets an example and provides a pathway for players, coaches and administrators to grow and develop.
"The time is right for new investors to help lead and move the club forward with a renewed commercial focus. The NBL is going ahead in leaps and bounds, the club must move with it and we have made the decision now to ensure the ongoing success and growth of the club."
NBL Owner executive director Larry Kestelman acknowledged the role the Blackwells have played in the NBL and the New Zealand sporting landscape.
"Paul and Liz have done an incredible job building the Breakers and the club is an integral part of the NBL and our future plans to continue build success on both sides of the Tasman."
The Blackwells say it will be business as usual around the club.
"It is imperative any new investors are given the chance to be in control of the club at the end of this season, not the start of next season.
"While there may be some due diligence behind the scenes, nothing changes in our day to day operations or our quest for another championship."
Breakers timeline
2003 - Club forms.
2005 - Paul and Liz Blackwell take ownership; Andrej Lemanis is appointed coach.
2008 - The club qualifies for the NBL post-season for the first time.
2011 - The first NBL championship, defeating Cairns in the grand final.
2012 - Breakers include Spark Arena as a home venue, with a club record 9,285 attending game three of the grand final series win over Perth.
2013 - The third championship with victory over Perth.
2015 - A fourth championship is won under the coaching of Dean Vickerman.
2016 - Foundation player Paul Henare is named head coach.
2017 - The Blackwells prepare to relinquish majority ownership in the club.
