In a statement, TVNZ's Head of News and Current Affairs, John Gillespie, said "weekends would not be the same without Bernadine".
He paid tribute to her "significant contribution" to TVNZ, including her coverage of Olympic and Commonwealth Games, Rugby and Netball World Cups and numerous news and sports anchoring roles.
Oliver-Kerby could not be reached for comment.
The move marks the third high profile departure from the broadcaster in three months.
Weather presenter Karen Olsen left the network in October after more than two decades at TVNZ. Likewise, Good Morning host Jeanette Thomas was made redundant when the morning show was cancelled. Its final episode screened in December.
Earlier this month, media commentator Janet Wilson said the move signalled a pattern of behaviour by TVNZ and came as no surprise.
"There is a casual sexism at play ... Women of a certain age are deemed no longer valuable."
She said there is a pattern of "culling" every nine to 10 years, which sees older female presenters removed from on air.
In 2005, both Judy Bailey and Susan Wood left their roles as prime time presenters for TVNZ.
- nzherald.co.nz