The operator of the troubled Fukushima No. 1 nuclear power plant on Thursday asked the Japanese government for a capital injection of 1 trillion yen (about 12.1 billion U.S. dollars) to avoid insolvency amid rising costs of fuel and decontamination.

The move is widely believed to be a start button for a process that will enable the government to control the Tokyo Electric Power Co., known as TEPCO.

TEPCO President Toshio Nishizawa told a press conference that his company's financial status has become extremely severe and such an injection is vital for it to stay afloat.

The capital injection is expected to take place possibly in July, making it the largest bailout outside the banking sector in Japan, Kyodo News reported.

The cash injection will be given to the company in exchange for stake. The TEPCO is scheduled to hold a shareholder's meeting in late June, when a resolution is expected to be passed regarding the size of the stake for the government, according to local media reports.

The operator, which is behind the world's worst nuclear accident since Chernobyl, also sought 845.9 billion yen in aid of funding its swelling compensation costs, raising the amount of public fund for compensation to around 2.5 trillion yen.

Restarting nuclear reactors in Japan is difficult because the nuclear accident at the Fukushima plant has generated concerns about the safety of nuclear power.