Sinohydro plans to issue up to 3.5 billion new shares to raise cash to fund 17.3 billion yuan ($2.7 billion) in new projects, according to the company's draft IPO prospectus.

It will not be clear exactly how much Sinohydro will raise until it sets its IPO price.

The regulator said in a statement it had approved the IPO plan, confirming what a source had told Reuters earlier. It did not elaborate further.

The new issue would represent close to 35 percent of its expanded share capital, with the funds being used for equipment purchases and investments in clean energy projects, the prospectus said.

Sinohydro is a leading dam builder in China, having built 65 percent of the medium- and large-sized dams in the country, including the Three Gorges dam on the Yangtze River and the Xiaolangdi dam on the Yellow River.

As part of an overseas expansion drive, the firm has taken on projects in Malaysia, Sudan, Laos and Ghana, according to the company's website.

It is also involved in other infrastructure projects, including the recently launched Beijing-Shanghai high-speed rail link, it said on its website.

Sinohydro Corp posted operating revenue of 101 billion yuan and net profit of 2.91 billion yuan in 2010.

China Securities Co and Bank of China International are the lead underwriters for the listing.