The 30-year-old Sinclair, who averages 36.89 in 25 tests, received a contract after missing out 12 months ago. ''Mathew Sinclair was last year asked by the selectors to go back to domestic cricket and prove himself,'' New Zealand general manager Lindsay Crocker said in a statement.
''He did that and is now seen as an international option, particularly as a test player.'' 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.
Adams returns to the list of contracted players after a two-year absence. Jamie How, Peter Fulton, Ross Taylor and Michael Mason were included for the first time.
Among players not offered contracts who were on last year's list were all-rounder Chris Cairns, who has retired, injury-plagued seamer Daryl Tuffey, batsman Craig McMillan and one-day veteran Chris Harris.
''Craig McMillan was unlucky not to be offered an NZC contract, having missed out by a slender margin,'' 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.
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.