Voter turnout for the election was the third lowest in more than 30 years but higher than in 2011.
The Electoral Commission has released preliminary results based on the 2,112,522 votes counted last night.
Special votes still to be counted are estimated at 293,130 including 38,500 overseas votes, which is 12.2 percent of the total number of votes.
If that figure holds, the turnout will have been 77.02 percent of those enrolled to vote, compared with 74.2 percent in 2011.
Statistics New Zealand figures since 1981 show only 2002 had a comparably low figure, with a turnout of 77 percent.
The Commission said the official results process is expected to be completed in 14 days.
