All other species except blue sharks would be protected from October 2015. The finning ban would apply to blue sharks from October 2016.
The tighter deadline was due to an overwhelming public response, ministers said.
Around 45,000 submissions were received on the proposal.
Dr Smith said: "Sharks may not be as cute and cuddly as our kiwi and our kakapo but we have 113 species of shark in our waters, a significant number of them are endangered and this additional protection will ensure their survival.
"The 45,000 submissions the public has made... shows that New Zealanders have matured in their attitude to the oceans a great deal from the 'Jaws' days when the only good shark was a dead shark.
"This measure of phasing in a ban on shark finning is also very important for New Zealand's clean, green reputation."
The plan was likely to cause some controversy because blue sharks were one of the most vulnerable species to the finning practice.
Between 50,000 and 150,000 blue sharks were believed to be killed in New Zealand waters every year. They were included in New Zealand's quota management system but total population numbers were not known because a stock assessment has never taken place.
Mr Guy said blue sharks were a highly migratory species and were usually caught as bycatch on tuna long-lines. Government would consult with industry and consider new technology to reduce shark bycatch.
Dr Smith said fishers had expressed some concern about how to safely release blue sharks alive.
Finning of live sharks was banned in 2009, but fishers are still able to cut fins off dead sharks and throw away the carcass.
The new regime requires fishing companies to release sharks alive or bring them ashore with fins attached for processing.
New Zealand is among the world's top 20 exporters of shark fins, most of which are sent to Asia to be made into a popular delicacy or traditional medicines.
Seven species are already completely protected under the Wildlife Act: great whites, basking shark, deep water nurse shark, spine-tailed devil ray, manta ray, whale shark, and oceanic whitetip shark.
The first tranche of species will be protected from finning in October this year.
A second tranche of sharks will come under the ban in October 2015, and the blue shark a year later.
