John Wright has cited differences with New Zealand's director of cricket, John Buchanan, as a key factor in his decision not to extend his contract as the head coach. Wright has been in the position for only 16 months but has turned down a proposal to stay on beyond August, when his contract expires, meaning the upcoming tour of the West Indies will be his last engagement as coach of New Zealand.

During Wright's time in charge, New Zealand have played nine Tests for three wins, three losses and three draws, and they reached the semi-finals of the World Cup last year. The highlight was the team's first victory in a Test in Australia for a quarter of a century, and that was followed by a respectable performance against South Africa, who won 1-0 in New Zealand.

But despite such encouraging results, Wright said he was ready to move on and that it was best to make way for a coach who could steer the side through to the 2015 World Cup, which he could not envisage himself doing. He also said differences between himself and Buchanan, who was appointed director of cricket several months after Wright took over as coach, had played a part.

"During the review process with the current cricket director, we both agreed the planning systems that he wants to implement don't complement the style and the way I coach, so that was another factor," Wright told reporters in New Zealand on Tuesday. "It's part of sport. I've enjoyed the opportunity to coach the New Zealand cricket team.

"I've looked at it from my point of view, the way I coach and the values and beliefs that I bring to the job. It's very important that I'm true to myself ... We see things a little differently. It would be fair to say we're probably more comfortable coaching against each other, which we did for four and a half years. But it's part of sport."

Wright became coach in December 2010, replacing Mark Greatbatch on a contract of less than two years. In April 2011, Buchanan was brought in to the newly-created role of director of cricket and was handed a four-year contract and a wide-ranging brief to oversee the high-performance programme and introduce consistent coaching strategies.

Asked to outline the differences in approach between himself and Buchanan, Wright said: "I think he's probably in a better position to do that. We're probably not that different, we just see things a little differently. As I explained earlier, the planning systems that John wants to implement are probably suited to another head coach. I think it's just a difference of style. We see things very differently. I wish him and everyone else success."

Wright, 57, has the chance to finish on a high with the July-August two-Test tour of the Caribbean, which will give New Zealand an opportunity to finish his tenure by jumping ahead of West Indies on the ICC Test rankings. David White, the NZC chief executive, said it was disappointing Wright had decided to end his time as head coach and the challenge would now be to find a mentor who could guide the side to the 2015 World Cup.

"John has been an outstanding servant for cricket in New Zealand over a long time and it is disappointing to lose someone of his calibre," White said. "We were keen to see him continue his head coach role, however we understand and respect his decision to look for another challenge.

"The fighting performance of the Black Caps at the ICC Cricket World Cup 2011 and again in the Test victory over Australia spoke volumes about John as a coach and he can be proud of the way he has advanced the current team. I would like to congratulate John on the contribution he has made and wish him all the best in his future endeavours."