Green bond sales are set for a record year as investors in clean-power and climate projects seek long-term gains from the securities.

With $US6.03 billion ($6.7 billion) of bonds sold since January, the securities are on course to surpass $US9 billion this year, beating the record $US7.5 billion sold in 2010, according to data compiled by Bloomberg. Issues include $US1 billion by MidAmerican Solar, a subsidiary of Warren Buffett-controlled Berkshire Hathaway's Mid-American Energy, to build and operate the Solar Star projects in California. The European Investment Bank has sold $US1.3 billion of green bonds this year.

Investors are snapping up bonds to finance the global expansion of clean energy, promoted by governments from the US to China to tackle climate change. The debt, issued by development banks or by project sponsors themselves, offers investors an alternative to volatile equities while boosting funding prospects for developers as nations from Spain to Romania have reined in support for the industry.

“There is a rising demand on the part of US insurance companies, money managers and pension funds for quality infrastructure and project finance projects,” Nasser Malik, head of global structured debt at Citigroup Inc., which underwrote 50 per cent of the MidAmerican Solar bond, said by phone Aug. 19. “The longer duration of the credits is a good match if you're managing a liability profile.”

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