Unions representing drivers at Auckland's biggest bus company say the workers and management still haven't reached a decision over a new collective agreement.
About 900 staff at NZ Bus voted against accepting the company's new pay offer at a stopwork meeting earlier in July.
Tramways and First unions met with NZ Bus on Thursday and Friday in an bid to reach an agreement.
First union spokesperson Karl Andersen says some progress was made but says he cannot reveal much else until mediation is over.
NZ Bus is offering a three year pay deal with the first instalment of a 2.3% increase in November.
The parties will resume further negotiations later this month.