The two companies, which have previously said they were in talks over the deal, will hold a news conference later on Monday, the business daily said.

The acquisition would allow Hitachi to boost its global presence in the power grid industry, while ABB, which also makes industrial robots, wants to offload its least profitable division to focus on areas such as automation.

A Hitachi spokesman declined to confirm the report, saying it was not something the company had announced.

A source familiar with the situation has valued the power grid business at between $10 billion and $12 billion.

Other sources have said that ABB could keep a stake in the power grid business via a joint venture with Hitachi.

The Nikkei reported that the deal would see Hitachi pay 600 billion-800 billion yen ($5.3 billion to $7 billion) for an initial 50 percent stake in the business.

ABB's power grid business employs 36,000 people and had sales of $10.4 billion last year. It had an operating profit margin of 10.0 percent in the third quarter, down 60 basis points from a year earlier.

The decision to sell it marks a U-turn for ABB Chief Executive Ulrich Spiesshofer, who decided to keep the business two years ago despite calls from some shareholders to sell.