Some top players are delaying signing new contracts with New Zealand Cricket over concerns the team's international program next season will conflict with their lucrative roles in the Indian Premier League, local media reported on Thursday.

The New Zealand Herald newspaper named wicketkeeper Brendon McCullum and all-rounder Jacob Oram _ New Zealand's highest-paid players in the IPL _ among players who were hesitant to sign contracts until dates for the next IPL tournament had been released.

The newspaper said players were concerned New Zealand's home series against Australia in March and April next year may clash with the Indian Twenty20 league. McCullum currently earns up to $700,000 and Oram $675,000 to play in the IPL, although the amount players receive is based on the number of games they play.

New Zealand Cricket chief executive Justin Vaughan told the Herald players had until July 24 to sign contracts and he was confident all 20 players offered contracts last month would sign.

Vaughan said concerns over a clash between the Australian tour and the IPL were speculative because no dates for the Indian tournament had yet been set.

The Australia tour is likely to stretch into the first week in April and it seems likely the IPL favored an early-April start date, the newspaper said.

"We haven't had any official indications from the players that there are any of these concerns," Vaughan said.

Six players offered contracts by New Zealand Cricket played in the last edition of the IPL _ McCullum, Oram, captain Daniel Vettori, Jesse Ryder, Ross Taylor and Kyle Mills. Vaughan refused to say whether any of those players had yet to sign new contracts.

New Zealand Players Association boss Heath Mills said some players were seeking clarity around schedules before signing New Zealand contracts.

"I am not aware of the final dates of the IPL, and the dates of the Australian series have not yet been finalized, but I would expect players would likely want to get some clarity around these," Mills told the Herald.