Nikkei hits 1-mth closing low on yen, loss reports

* Nikkei down 4.8 percent for lowest close in a month

* Sony tumbles after loss prediction, Toshiba also hit

* Exporters slide as yen rises

* Reality of weak economy outweighs hopes for new U.S. govt (Adds USJ)

By Elaine Lies

TOKYO, Jan 13 (Reuters) - Japan's Nikkei average fell 4.8 percent to its lowest close in a month on Tuesday, hit by a stronger yen that nailed exporters as worries about earnings of major firms fuelled fears about the global economy.

Sony Corp (6758.T) tumbled nearly 9 percent after a source said it was expected to post an operating loss of about 100 billion yen ($1.1 billion) for this business year, far short of the company's forecast of a 200 billion yen profit. [ID:nT345549]

Toshiba Corp (6502.T) also slid on a similar report of a big loss while Canon Inc (7751.T) tumbled after its chairman said year-end holiday sales were disappointing.

But USJ Co Ltd 2142.T, the operator of a Universal Studios theme park in Japan, soared almost 12 percent after five people familiar with the matter said the company may go private in a buyout led by Goldman Sachs (GS.N). [ID:nT145772]

Market players said recent buying based on hopes for the administration of U.S. President-elect Barack Obama, which had underpinned a global rally in the New Year, had lost steam in the face of signs that the global economic situation remains dire.

"These worsening forecasts aren't just a Japanese event, we're seeing the same thing happen in the United States, and it's pushing the dollar lower against the yen," said Masayoshi Okamoto, head of dealing at Okasan Securities.

"Though stock markets rallied briefly around the end and beginning of the year, it's clear now that the worsening of the real global economy is far outweighing expectations for the new U.S. administration."

The dollar was struggling to hold its own against the yen, fetching around 89.29 yen -- barely above Monday's three-week low of 88.89 yen, which itself was not far from December's 13-½ year trough just above 87 yen. JPY=

Fears of dismal fourth-quarter earnings by U.S. firms were fed by a Wall Street Journal report that Citigroup could report more than $10 billion in fourth-quarter operating losses and by a wider-than-expected loss at Alcoa Inc (AA.N). [.N]

The benchmark Nikkei .N225 fell 422.89 points to 8,413.91, its lowest close since Dec. 12 and its third straight trading day of losses, the biggest losing streak since mid-November.

The broader Topix shed 4.8 percent to 814.12.