Tokyo stocks lost 0.84 percent on Wednesday morning, hit by worries over the lack of progress in resolving a US budgetary impasse that threatens to send the world's biggest economy into recession.
The benchmark Nikkei 225 index at the Tokyo Stock Exchange lost 79.37 points to 9,343.93 by the break, while the broader Topix index of all first-section issues sank 0.85 percent, or 6.64 points, to 774.96.
Investors locked in profits from recent gains caused by the yen's weakening trend, usually a boost for Japanese shares, which reversed course on worries over the US fiscal cliff.
The package of spending cuts and tax hikes -- scheduled to come into effect on January 1 unless a deeply divided US Congress strikes a new budget deal -- will likely throw the world's biggest economy into recession.
"The difficulties with solving the US 'fiscal cliff' are coming to a head again and may present a good selling opportunity for investors," Kenichi Hirano, market analyst at Tachibana Securities, told Dow Jones Newswires.
US stocks fell Tuesday as fiscal cliff worries overshadowed encouraging economic data, while investors shrugged off an agreement on Greece's new batch of bailout cash.
The Dow Jones Industrial Average shed 0.69 percent to end at 12,878.13.
Also Tuesday, the OECD in its latest economic outlook warned that global growth is set for a sharp slowdown next year, with the eurozone debt crisis remaining the "greatest threat" to the world economy.
In Tokyo trade, Fujitsu was down 1.63 percent at 300 yen as the leading Nikkei business daily reported the IT giant will pump 100 billion yen ($1.22 billion) into the underfunded pension plan of its British unit Fujitsu Services.
Major exporters fell as the yen strengthened, with Canon down 2.09 percent at 2,845 yen and Honda Motor off 1.28 percent at 2,693 yen.
On currency markets, the euro bought $1.2927 and 105.79 yen, weakening from $1.2938 and 106.30 yen in New York late Tuesday.
The dollar was at 81.79 yen against 82.16 yen.