TOKYO, Oct 27 (Reuters) - Japan's Nikkei average lost 1.5 percent on Tuesday, its biggest one-day percentage fall in three weeks, as trading houses fell after oil slid and Astellas Pharma (4503.T) was hurt by a brokerage downgrade. Blue-chip exporters such as Honda Motor Co (7267.T) also dragged on the market after U.S. stocks fell on chances that lawmakers may let a federal home buyer tax credit expire, raising fears the U.S. housing industry may lose a crucial incentive that has spurred hopes of stabilisation in recent months. [.N]

Both Chuo Mitsui Trust (8309.T) and rival Sumitomo Trust (8403.T) climbed after the Nikkei business daily said the two planned to merge in early 2011. Trading in their shares was subsequently suspended by the Tokyo Stock Exchange. [ID:nTFA006475]

As Japan's earnings season moves into high gear, analysts said that while generally solid results were supporting the market concerns about the global economy lingered. Even though the actual earnings we've seen haven't been too bad, there's a lot of uncertainty about the second half of the year, with pretty conservative forecasts, said Hiroaki Osakabe, a fund manager at Chibagin Asset Management. In addition, I think there's a worry that economic growth may be slowing a bit in the shorter term, leading to selling. The benchmark Nikkei .N225 lost 150.16 points to 10,212.46 and marked its biggest one-day percentage drop since Oct. 2. The broader Topix lost 1.7 percent to 895.48.

Honda, which announced earnings after the bell, nearly tripled its annual profit forecasts as second-quarter earnings fell less than forecast, thanks to government stimulus schemes around the world that boosted sales. [ID:nT324227]

Canon Inc (7751.T), also announcing earnings after the close, posted a 54 percent drop in quarterly profit as weak copier demand outweighed robust digital camera sales, and stuck to its annual forecast for a 62 percent decline. [ID:nT203059]

The result, while in line with market expectations, underscores tight spending budgets by corporations.

U.S. stocks fell for a second straight session on Monday as investors sold shares in home builders and financials, while commodity shares succumbed to pressure from a higher dollar.

There's a bit of worry that global shares may be headed for a simultaneous correction, given that they've all been rising together for a while, said Takashi Ushio, head of the investment strategy division at Marusan Securities.

After all, the U.S. earnings and indicators that have recently come out haven't seemed to be bad enough to cause the slide of the last few days. It appears to have been more caused by concern that stocks have risen too far.

Along with corporate earnings, economic indicators are a big focus this week, market players said. On Thursday, Japan will announce its industrial output data for September and the U.S. government will report its first estimate of third-quarter gross domestic product.

ASTELLAS FALLS, OIL WEIGHS

Shipping firms, including Japan's No.1 Nippon Yusen KK (9101.T), dropped after they cut their income forecasts for the year to March, citing a sluggish recovery in key freight rates for dry bulk ships and rising fuel costs.

Nippon Yusen KK fell 2.5 percent to 347 yen, Mitsui O.S.K. Lines Ltd (9104.T) lost 2.5 percent to 551 yen and Kawasaki Kisen Kaisha Ltd (9107.T) sank 6.4 percent to 353.

Astellas dropped 6.7 percent to 3,340 yen after Barclays Capital cut its rating on the No.2 Japanese drugmaker to underweight from equal weight, citing tougher-than-expected competition with generic drug makers.

Barclays reduced its target price for Astellas shares to 3,100 yen for the next 12 months from 3,500 yen, saying a generic version of Astellas' transplant drug prograf was taking market share from the company faster than expected. [ID:nT344249]

Oil and gas developer Inpex Corp (1605.T) fell 1.6 percent to 778,000 yen after oil prices declined for a fourth day to stand below $79 a barrel on Tuesday, hurt by a stronger dollar and concerns that a sluggish economic recovery would keep fuel demand low. [O/R]

Trading houses, which are major dealers in energy and have stakes in oil and gas projects, also slid.

Mitsubishi Corp (8058.T), Japan's largest trading house, lost 5.5 percent to 1,962 yen, while fellow trading house Mitsui & Co (8031.T) tumbled 4.9 percent to 1,243 yen and Marubeni Corp (8002.T) skidded 3.9 percent to 465 yen.

But Fujifilm Holdings (4901.T) bucked the trend, rising 6.6 percent to 2,600 yen after Nomura Holdings raised its rating on the maker of digital cameras and high-tech film used in LCD panels, citing progress with structural reforms and hopes for better than expected earnings for the second quarter.

Trade was moderate, with 1.92 billion shares changing hands on the Tokyo exchange's first section, roughly in line with last week's daily average.

Declining shares outpaced advancing ones by more than 5 to 1. (Additional reporting by Aiko Hayashi; Editing by Michael Watson)

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