Sinclair has prospered in domestic cricket this year

The prolific right-hander, who has made two double centuries in 25 Tests, was one of seven players added to the list who were not included for 2005-2006.

Essex all-rounder Andre Adams also wins a contract after a two-year absence.

The newcomers are batsmen Peter Fulton, Jamie How and Ross Taylor, spinner Jeetan Patel and paceman Michael Mason.

Apart from Chris Cairns, who retired last year, Craig Cumming, Chris Harris, James Marshall, Daryl Tuffey, Craig McMillan and Paul Wiseman have not been offered new contracts.

"Craig McMillan was unlucky not to be offered a contract, having missed out by a slender margin," New Zealand general manager Lindsay Crocker said.

"He remains in contention for selection, particularly in the one-day game."

Harris, 36, has been a mainstay of New Zealand's one-day side for years, playing 250 matches since making his debut in 1990, but has suffered recent injury problems.

"It is the selectors' view that Chris Harris has been overtaken by other players in his role as a finisher with the bat in one-day games and as a slow bowler," Crocker said.

The 30-year-old Sinclair, whose Test average is 36.89, was last year "asked by the selectors to go back to domestic cricket and prove himself," Crocker explained.

"He did that and is now seen as an international option, particularly as a Test player," he added.

Sinclair was New Zealand's leading first-class domestic batsman in 2005-06, scoring three centuries and five fifties in 16 innings at an average of 51.64.

He had said he was considering a move overseas to South Africa or Australia.

Contracted players: Andre Adams, Nathan Astle, Shane Bond, Stephen Fleming, James Franklin, Peter Fulton, Jamie How, Hamish Marshall, Chris Martin, Michael Mason, Brendon McCullum, Kyle Mills, Jacob Oram, Michael Papps, Jeetan Patel, Mathew Sinclair, Scott Styris, Ross Taylor, Daniel Vettori, Lou Vincent.