Japan's Cabinet on Wednesday stopped short of committing to phase out nuclear power by 2040, backtracking from an advisory panel's recommendations in the face of opposition from pro-nuclear businesses and groups.

The decision came the same day Japan launched a new regulatory body to replace the agency whose lack of independence from the nuclear industry was blamed for contributing to last year's disaster.

While not endorsing the energy policy document calling for the phase-out released last week, the Cabinet ministers did vaguely agree to pursue its goals. The advisory panel, acknowledging public aversion to nuclear power since the Fukushima accident, had called on Japan to phase it out within three decades through greater reliance on renewable energy, more conservation and sustainable use of fossil fuels.

The Cabinet said only that it would take the policy document "into consideration" and would seek public support for the goals, while continuously reviewing the process and also trying to gain understanding from the international community. But the public in this case includes not only the general public, which has come out strongly against nuclear power, but also the nuclear industry and other business interests, as well as communities near nuclear plants that rely on them economically.

National Policy Minister Motohisa Furukawa said the gist of Japan's energy policy remains to phase out nuclear power, though it would take time. Furukawa vowed to push for green energy and to seek to curb carbon dioxide emissions.

The Cabinet's ambiguous endorsement has added to criticism that the policy revision may just be intended to win votes in elections expected within the next few months.

But business leaders praised the Cabinet's perceived backpedalling.

"It seems that (the Cabinet) did not mention specific targets such as 2030s or zero per cent, so I assume we could avert the problem for the time being," said Masahiro Yonekura, chairman of an influential business lobby Keidanren, told reporters. In his last-ditch protest Tuesday, Yonekura called the phase-out plan "totally unacceptable" and threatened to quit a government panel he is representing a business group.

Nuclear energy made up about a third of the country's electricity before the March 11, 2011, earthquake-tsunami caused reactor meltdowns at the Fukushima Dai-ichi plant, and Japan had planned to increase that to 50 per cent. Now nuclear power is highly unpopular, and only two of the country's 50 functioning reactions are on line while the government addresses public concerns about safety.

The new regulatory agency inaugurated Wednesday was delayed months by demands from opposition lawmakers for more dependency as well as opposition to appointees' pro-nuclear background. The five-member Nuclear Regulation Authority is headed by nuclear physicist and Fukushima native Shunichi Tanaka.

Opposition lawmakers and activists have raise questions about his credentials because he had been executive of the Japan Atomic Energy Agency, which promotes development of nuclear energy.

Tanaka, 67, has helped decontaminate areas around the Fukushima plant contaminated with radiation. But he is unpopular among some residents who say he has downplayed the potential risk of low-dose radiation exposure.

The nominees for the four other committee members are a current JAEA official, a radiation expert, a seismologist and a former diplomat who participated in a parliamentary investigation into the Fukushima crisis.

Their appointments also triggered huge public protests because Prime Minister Yoshihiko Noda decided without going through required parliamentary approval to meet the committee's Sept. 26 launch deadline.

The new unit combines the former regulator Nuclear Industrial and Safety Agency, the Nuclear Safety Commission and several other nuclear-related government departments. The new entity is attached to the Environment Ministry, a move intended to distance the regulators from the influence of nuclear energy promoters. NISA was in the industry ministry, which also promotes nuclear energy.

Several investigations have said collusion between the regulators and the utility that ran Fukushima helped set off the worst nuclear disaster since Chornobyl.

The energy policy the Cabinet advisory panel proposed last Friday calls for greater reliance on renewable energy, more conservation and sustainable use of fossil fuels to achieve a nuclear-free society by 2040.

Such a reversal of Japan's decades-long advocacy of nuclear power is popular with the public, but faces strong resistance from powerful business interests and communities where nuclear plants are located are loath to give up their huge government subsidies.

To blunt outright opposition, the energy plan left many details undecided, and among the biggest are spent fuel processing and radioactive waste disposal. That allows a fuel recycling program at a plant in northern Japan's Rokkasho to continue. It also leaves unanswered how Japan will avoid accumulating stockpiles of spent plutonium in violation of its non-proliferation commitments.

The proposed phase-out of nuclear power by the 2030s was to be achieved mainly by retiring aging reactors and not replacing them. It calls for limiting each reactor to a 40-year lifespan and for building no more new reactors.