Claudio Facchin, the head of Power Grids, signed memorandums of understanding with Chinese companies including State Grid Corporation of China [STGRD.UL] and China Southern Power Grid [CNPOW.UL] earlier this month, the source said.

A spokesman for ABB confirmed the agreements, but declined to comment on the financial details.

The agreements will bolster ABB's Power Grids division as the Swiss engineering group seeks a buyer for the business.

The China deal includes digital software and components for high voltage direct current systems used to transmit electricity over long distances, the source said.

Deliveries could include components for a 1,200-km (746 miles) high voltage power line between Inner Mongolia and Shandong province.

Reuters reported last week that ABB was in advanced talks with three suitors for the Power Grids division, which could be worth around $11 billion including debt.

A source told Reuters this week that Japan's Hitachi is the front-runner to buy the business.

A decision to sell Power Grids, which makes transformers and substations for transmitting electricity, marks a reversal for ABB after it decided to keep the business two years ago despite calls from some shareholders to sell.

(Reporting by John Revill, editing by John Miller and Susan Fenton)

By John Revill

Stocks treated in this article : Hitachi, Ltd., ABB Ltd