Harvie, who was the first chairman of the board after it was re-organised following its flirtation with liquidation, has been replaced by Andrew Rooney.
Harvie will continue as a board member.
Harvie, who has resigned with immediate effect, is also working with the New Zealand Rugby Union to get private equity into the Highlanders and said that role conflicted with his role as chairman.
Harvie has one more year left in his three-year term as a board member and he was undecided whether he would continue after that.
''I have always said I would not be there for a long time and the job is largely done now. We set out wanting to get back up and running and put some accountability in place,'' he said.
''We have now put some money in the bank and got some robust systems in place. We have people in there who know what they are doing and now is the time for me to do other things.''
Harvie (56) is now a member of the Highlanders board as a representative of the Otago union and said there was plenty of water to flow under the bridge before a private licence is granted to the southern franchise.
He is helping co-ordinate southern interests in putting a financial stake in the Highlanders.
But that role was taking up time and did not sit well with his position as the chairman of the Otago union.
''I just can't do the two things at the same time. It is a major thing being chairman of the Otago rugby union and it just conflicts with what I am doing with the Highlanders.''
He said it took a while before making the decision to step down.
''I had to be satisfied that all the in-house was working the way I thought it should be and it is. It was not an easy decision to make and it did not happen overnight.''
The Otago union flirted with liquidation in early 2012 and was days away from going out of business.
Harvie became chairman in mid 2012 after the union had been saved and had been an key part of the union's financial turnaround.
It produced a healthy profit for the 2013 year of more than $400,000, an outstanding achievement considering the union had debts of more than $2 million in early 2012.
Harvie, a Dunedin chartered accountant, said the union was now looking to grow the game and it was time for someone who had the skills to do this to be chairman.
He said the obvious highlight off the field was turning the union around financially while on the field the highlight was winning the Ranfurly Shield last year.
Harvie will still be a member of the board's audit risk committee.
Rooney, a Dunedin investment adviser, was on the board when the union faced going out of business.
The position of chairman was voted for in a secret ballot by the eight board members.
