* Nikkei up on short-covering in thin trade after Monday fall
* Support seen solid at 10,100, near 25-day moving average
* Commodities-linked shares down after metals, oil drop
* Shanghai shares edge up briefly, cheering investors
By Elaine Lies
TOKYO, Aug 18 (Reuters) - Japan's Nikkei stock index clawed back from its lowest close in almost two weeks on Tuesday as short-covering emerged, with investors encouraged as Shanghai shares edged higher after tumbling the previous day.
Mitsubishi Corp <8058.T> and other trading houses lost ground after commodities fell on growing doubts about economic recovery, though this was countered by gains in defensive shares -- seen as resilient in the face of economic uncertainty -- such as telecommunications and retailers.
But the big focus was China after shares there plunged 5.8 percent on Monday. The Shanghai Composite Index <
> drifted in early trade, swinging from positive to negative territory.Tokyo analysts were a bit sceptical about how much weight should be placed on Chinese share movements, noting that sharp gains in global markets last week had primed them for profit-taking.
"There is a bit of concern in markets about whether the positive impact of various government stimulus programmes hasn't already peaked out and whether the signs of economic recovery can be sustained into 2010," said Hiroaki Osakabe, a fund manager at Chibagin Asset Management.
"Mainly, though, everyone was looking for a good time to take profits after the recent gains -- and China provided the reason."
On Monday, Shanghai shares closed down 176.342 points at 2,870.630, extending last week's 6.6 percent drop. They were down 0.2 percent by the end of morning trade in Tokyo.
U.S. stocks fell the most in seven weeks on Monday after a sell-off in major Asian markets fed into a drop in European stocks, with a disappointing outlook from retailer Lowe's Cos <LOW.N> stoking worries about weak U.S. consumer spending.
"I think macroeconomic indicators in general suggest things are improving globally and there's no reason to be so pessimistic, but there's not a lot we can do about market sentiment as long as stocks keep on falling," said Noritsugu Hirakawa, a strategist at Okasan Securities.
"If Shanghai manages to stabilise above 2,800, I think the Nikkei will rise a bit, mainly on short-covering."
The benchmark Nikkei <
> had gained 0.4 percent or 38.80 points to 10,307.41 by the midday break. It closed at 10,268.61 on Monday after falling 3.1 percent, its biggest one-day percentage fall in nearly five months.The broader Topix <
> gained 0.1 percent to 950.46.WATCHING SUPPORT
Market analysts said they expected support to hold for the benchmark Nikkei <
> around 10,100, or just a bit above the 25-day moving average, which currently comes in around 10,038.Little impact is expected from the start of campaigning for an Aug. 30 election for Japan's lower house of parliament, which polls show the opposition Democrats have a good shot at winning.
"This will be neutral for the market at this point, although the start of the campaign means we have a bit of a political vacuum, which can't be said to be good," said Kenichi Hirano, operating officer at Tachibana Securities.
Sumitomo Mitsui Construction <1821.T> and IHI Corp <7013.T> gained after a report in the Nikkei business daily that the two firms had won a 40 billion yen order to build a bridge in Vietnam.
Sumitomo Mitsui, a general contractor, soared 8 percent to 108 yen and IHI, a heavy machinery maker, gained 1.7 percent to 177 yen.
Casio Computer Co Ltd <6952.T> jumped 5.8 percent to 788 yen after Credit Suisse lifted its rating to "outperform" from "underperform", saying the brokerage expects an earnings recovery in the firm's loss-making businesses including mobile phone handsets.
"We believe Casio shares offer a very good investment opportunity amid ongoing strong market skepticism about an earnings recovery," Credit Suisse analyst Koya Tabata wrote in a research note.
But trading companies lost ground as metals and oil prices fell on Monday, with Mitsubishi Corp, Japan's largest trader, losing 2.2 percent to 1,880 yen.
Mitsui & Co <8031.T> fell 1.8 percent to 1,219 yen and Itochu Corp <8001.T> lost 1.8 percent to 655 yen.
Trade was thin, with 889 million shares changing hands on the Tokyo exchange's first section compared with last week's morning average of 932 million.
Declining shares outpaced advancing ones, 884 to 613. (Reporting by Elaine Lies; Editing by Chris Gallagher)