"The courts use it and a lot of documentation is translated into Maori, so there are definitely careers there for people who speak and write well."
Te reo was popular in Years 9 and 10, but numbers dropped after that as students perceived languages as too difficult at NCEA level, Mr Shepherd said.
Staff were working to boost the number of te reo students.
"It's one of New Zealand's languages, so we have an obligation to offer it."
Public Service Association national secretary Brenda Pilott said public servants were now rewarded for Maori language competency.
"We have a number of collective agreements that specify an allowance for people who are competent in te reo and are using that as part of their work."
There was an increasing expectation that public servants could carry out some business in te reo, and it was important that they could respond competently, Mrs Pilott said.
Maori language immersion schools could be partly credited for the shift, she said.
Business New Zealand chief executive Phil O'Reilly said while te reo was only directly helpful in a narrow range of businesses, Maori language knowledge demonstrated competence to employers.
"It demonstrates language learning capability and it demonstrates cultural awareness capability and that's very important for business, especially export businesses."
Employees who had learnt te reo were also more likely to have a better understanding of New Zealand history and a Maori perspective on different cultures, he said.
"That's very helpful as well because a lot of businesses are dealing with Maori customers or increasingly rubbing up against Maori issues."
While there was no noticeable uptake in te reo within the business community, growth of iwi organisations meant more senior level people would be picking it up, Mr O'Reilly said.
Census data from 2001 to 2006 revealed a drop in people's ability to hold an everyday conversation in Maori from 25.2 to 23.7 per cent.
Te reo Maori is not a compulsory part of the curriculum, but the Education Act requires schools to take reasonable steps to provide language instruction if parents ask for it. APNZ