WELLINGTON, Dec. 9 -- United States oil giant Chevron and the Indian government-controlled ONGC Videsh are among three new players to begin oil and gas exploration in New Zealand, the government announced in its controversial annual award of block offer permits on Tuesday.

Fifteen new oil and gas exploration permits were announced, prompting criticism and protests that the government promoting unsustainable fossil fuels and further endangering the world's most at-risk dolphin, the Maui's dolphin.

Energy and Resources Minister Simon Bridges said the six onshore permits and nine offshore permits collectively represented more than 110 million NZ dollars (83.75 million U.S. dollars) in committed expenditure on initial exploration, which, if successful, could lead to further work worth more than 1 billion NZ dollars.

The results showed New Zealand continued to cement its reputation as a key destination for investors in oil and gas exploration, Bridges said in a statement.

The third new entrant was a local company, New Endeavor Resources.

However, the opposition Green Party and conservation groups said the government was pushing the Maui's dolphin estimated to have a population of just 55 adults to the brink of extinction by giving the green light to oil drilling in their marine mammal sanctuary.

Other permits were in other ecologically protected areas and included the deepest well ever permitted in New Zealand as well as a permit that would allow oil drilling in deeper water than ever before anywhere in the world, Green Party energy spokesperson Gareth Hughes said.

"The government is putting the short-term interest of petroleum companies ahead of the thousands and thousands of New Zealanders who love and want to protect the endangered Maui's dolphin," Hughes said in a statement.

"At the same time as countries are meeting to plan reducing emissions the New Zealand government is handing out permits for oil exploration in the habitat of the world's most endangered dolphin."

After the announcement, activists from the Oil Free Wellington campaign group reported they had locked themselves to the entrance of the government's New Zealand Petroleum and Minerals agency headquarters in Wellington.

"The science of climate change is clear. We must act urgently to transition away from fossil fuels. We can't sit by while our government carves up our oceans and land for more fossil fuel exploration," Oil Free Wellington spokesperson Michelle Ducat said in a statement.

"The government should expect resistance to its planned expansion of fossil fuels."