Malaysia's ringgit led losses among emerging Asian currencies on Wednesday amid sustained concerns over a slowing Chinese economy with growth in the world's second-largest economy at a six-year low.

The ringgit fell to its weakest level against the US dollar in more than two weeks. Offshore funds sold the currency in non-deliverable forwards market as five-year government bond prices fell. The Malaysian unit hit a 17-year low against the Singapore dollar.

Investors bought the Singapore dollar versus the ringgit as the city-state's central bank on Tuesday unexpectedly held off from delivering more stimulus.

South Korea's won slid on dollar demand linked to local companies' dividend payments to foreign shareholders.

China grew at its slowest pace in six years at the first quarter and weakness in key sectors suggested the economy was still losing momentum, intensifying Beijing's struggle to find the right policy to support activity.

"There are still abundant downside risks. It doesn't bode well with Asia," said Andy Ji, Asian currency strategist for Commonwealth Bank of Australia in Singapore.

Potential monetary easing by China may not help Asian currencies much as fresh liquidity may not flow into the real economy and financial markets due to slowing global growth, Ji said.

"We have seen diminishing effects from past liquidity injections," he said.