China Three Gorges Corp, the operator of the world's largest hydroelectric power project, is joining a line of State-run Chinese companies looking to issue bonds overseas for the first time.

The company sent out a request for proposals in February and responses were due last week, said two sources familiar with the situation, noting that the offering could materialize in the second quarter.

The tenors and format of the offering had yet to be decided, Reuters reported. The issuer is looking at multiple currencies.

The deal underlines the determination of Chinese State-owned enterprises to reduce their reliance on domestic bank loans and bond markets, coming even as onshore funding costs have fallen sharply. The local 10-year government benchmark is down 30 base points since the start of 2015 and down 110 base points over the last 12 months.

The policy shift, which covers both companies keen to fund overseas expansions and others looking to bring back the proceeds to China, has caused a surge in international bond sales out of China in recent years.

In 2014, State-owned companies issued G3 bonds of $59.7 billion, up from $35.0 billion in 2013 and just $500 million in 2009, according to Thomson Reuters data.

While State champions, such as China Three Gorges, are able to tap into strong domestic liquidity in a market that expects further monetary easing, they are also aware that local markets can be volatile.

The company has relied entirely on domestic investors for its previous bonds. Its most recent transactions include a two-tranche offering of medium-term notes totaling 10 billion yuan ($1.63 billion) in March 2014, split between 5.5 percent 5 billion yuan three-year and 5.69 percent 5 billion yuan five-year comparable bonds.

Standard & Poor's affirmed its A long-term corporate credit rating on China Three Gorges last August and kept the outlook stable, while Moody's first rated China Three Gorges A1 with a stable outlook in August 2012.

Both credit agencies based their ratings on the company's strategic importance and 100 percent State ownership. S&P expects China Three Gorges to maintain its strong operating performance and continue to benefit from Chinese government support if the company experiences financial stress.

China Three Gorges' spending will increase significantly over the next three to five years due to resettlement and construction costs for mega-hydro projects Wudongde and Baihetan, according to the S&P report.