At the end of April, Shenhua had assets worth 1.04 trillion yuan and Guoadian had assets of 800 billion yuan, making the combined company worth 1.84 trillion yuan ($278.03 billion).

Here is a breakdown of each companies' operations:

GUODIAN GROUP:

Group had total installed capacity of 143 gigawatts of power, including 26.17 GW of wind at end-June. It is also leading hydropower and renewables developer and produced 58.72 million tonnes of coal in the first of the year.

Its listed unit GD Power (>> GD Power Development Co Ltd) has 22 coal fired power plants with capacity of 34.3 GW and has 7.6 GW under construction. Five of those operating plants lost money in the first half.

Other listed units of China Guodian are Guodian Changyuan Electric Power Co Ltd (>> Guodian Changyuan Electric Power Co. Ltd), Yantai LongYuan Power Technology Co Ltd (>> Yantai Longyuan Power Technology Co.,Ltd) and Ningxia Younglight Chemicals Co Ltd (>> Ningxia Younglight Chemicals Co Ltd)

SHENHUA GROUP:

Shenhua said on Monday it expects to produce 278 million tonnes of coal in 2017, down from a previous target of 290 million tonnes. It also set a sales target of 396 million tonnes for 2017.

Its website says end-2015 it had 54 coal mines; total installed power capacity 78.5 GW, 2,155 km of rail network and port cargo capacity of 270 million tonnes.

Shenhua's listed unit Shenhua Energy Co Ltd (>> China Shenhua Energy Company Limited) has 18 power plants with capacity of 33 GW and 3.9 GW under construction.

Seven of those were in deep loss in the first half. The listed company was one of the most profitable public commodity companies in the first half.

(Reporting by Josephine Mason and Meng Meng; editing by Susan Thomas)