Hong Kong shares opened with big losses Wednesday morning on worries hardline US lawmakers could torpedo a bipartisan deal aimed at lifting the debt ceiling to avoid a calamitous default.

The Hang Seng Index shed 0.97 percent to 18,415.

The Shanghai Composite Index gave up 0.30 percent, to 3,215, while the Shenzhen Composite Index on the mainland's second exchange lost 0.16 percent to 2,009. (AFP)