Colin Cooper quit the Waikato Chiefs Thursday with a year still on his coaching contract, saying he was leaving for the long-term good of the New Zealand Super Rugby team.
Cooper guided the Chiefs to the quarter-finals in the two seasons he was in charge but faced criticism earlier this year after the team made a poor start to their campaign.
He said he wanted to spend more time with his family and the time was right for someone else to take over.
"I believe the team and the club are bigger than the individual and the club comes first," he said.
"With next year the start of a new World Cup cycle, I believe it is the right time to step aside.
"There is a good crew of players and staff here who are committed to carrying the club forward."
The Chiefs, who won back-to-back titles in 2012 and 2013 but never looked like adding to their tally under Cooper, have not yet named a new coach.
A long-term prospect may be Waikato native Warren Gatland, who expressed interest in the job earlier this month when he announced he will coach the British and Irish Lions' tour to South Africa in 2021.
Gatland, who will step down as Wales coach after this year's Rugby World Cup, gave an emphatic denial when asked if he would join England after the Lions tour, but was more cagey about taking over at the Chiefs.
"At the moment I'm talking to a couple of people about what I'm going to do post the Lions but there's nothing that I've looked at signing or nothing formal at the moment," he told reporters in London.
Gatland was born in Hamilton and has a deep history with rugby in the region.
He racked up a record 140 appearances as hooker for Waikato before hanging up his boots in 1995, then coached the side in the domestic competition from 2004-2006.
He also worked as technical director at the Chiefs before departing for Wales, where he won three Grand Slams.