New Zealand Cricket bosses lamented the retirement from the Black Caps of the 36-year-old all-rounder after he was drafted to play for the Adelaide Strikers.
Zimbabwe-born De Grandhomme scored 1,432 runs in 29 Tests, also playing 45 one-day games and 41 Twenty20 internationals.
De Grandhomme follows key quick bowler Boult, who also asked to be released from his central contract and signed for Melbourne Stars in the BBL, one of the lucrative T20 tournaments worldwide that has sprung up.
Between them they have played over 100 Test matches and were two of the 20 centrally contracted players for the forthcoming season, including October s T20 World Cup in Australia.
The 33-year-old Boult kept his spot in New Zealand s squad for September s one-day internationals against Australia but New Zealand Cricket has said contracted players get priority in future selection.
Being under contract to New Zealand Cricket meant De Grandhomme and Boult had been ineligible to play in the BBL, which starts in December.
Bryan Stronach, head of high performance at New Zealand Cricket, said De Grandhomme was a loss.
“He s a dynamic player, he has his power-hitting, but he is an all-rounder and his accuracy with the ball is quite phenomenal,” he said.
Stronach is confident that other Black Caps will not follow the example of Boult and De Grandhomme.
“We don t think there is going to be a mass exodus or anything like that,” he told reporters, adding that their exit “creates opportunities” for up-and-coming players.