The call is contained in an open letter posted on the website of the Adil Soz (Right Word) media watchdog. The 44 signatories blame Ertysbaev for authoring what they say are restrictive amendments to the existing media law.
The changes came into force on July 21 amid widespread domestic and international criticism.
They make it more difficult for media outlets to get official registration. They also increase the number of reasons for denying a media outlet permission to operate.
Authorities have justified the changes by saying they aim to sanitize Kazakhstan's "overcrowded" media environment.
Kazakhstan is seeking to be elected the OSCE's next chair in 2009.