Sharp Corp forecast a record 290 billion yen ($3.8 billion) net loss for the year to March after posting surprise quarterly losses as a slump in TV sales forced it to halve output at a western Japan LCD plant.

The Japanese company said it was confronting a slump in both its LCD business, where it trimmed its full-year forecast for LCD TV sales to 12.8 million from 13.5 million, and in solar cells, which are also showing widening losses.

There had already been reports that it would slip into a loss, but the amount seems to be bigger than had been expected, said Takashi Hiroki, chief strategist at Monex Inc, adding there would be a strong negative impact on the stock after a market consensus for a net loss of about 15 billion yen.

Japan's manufacturing sector is facing a period of transition, so if Sharp goes ahead with structural reform of its operations, we can hold some hope of improvement in its results next year and beyond, added Hiroki.

Sharp had been expected to fare better than its bigger Japanese rivals Sony Corp and Panasonic Corp, which report earnings later this week, by focusing on premium big-screen TVs that have proved popular in the U.S. market.

But the company said its Sakai LCD plant would halve output for the January-March quarter, with the reduction likely to remain in place for the first half of the next financial year.

Japanese electronics makers are languishing in a TV market they once dominated as they confront sluggish demand and fierce competition from South Korean manufacturers that benefit from favorable exchange rates and aggressive investments.

In their home market, the Japanese have struggled with a stagnant economy, losing the boost they once got from a transition to terrestrial digital broadcasting and from subsidies for purchases of energy-efficient goods.

Sharp's Sakai facility in Osaka, capable of making the equivalent of 1.3 million panels a month for 40-inch TVs, was idled for about a month from April 2011.

The Nikkei business daily reported on Wednesday that the facility would cut output in half due to building inventories, spurring a slump in Sharp's share price.

Shares of the maker of Aquos LCD TVs ended Wednesday trade down 4.3 percent at 628 yen, compared with a flat benchmark Nikkei average. Since the start of last year, Sharp's shares have fallen 25 percent, compared with a 14 percent drop in the Nikkei.

For the full financial year to March, Sharp cut its operating profit forecast to zero from 85 billion yen. That compares with the 68.6 billion yen consensus forecast of 23 analysts polled by Thomson Reuters I/B/E/S.

For the October-December quarter, Sharp posted an operating loss of 24.45 billion yen, compared with a 23.03 billion yen operating profit in the year-ago period.

Rival Toshiba Corp booked a 72 percent fall in quarterly operating profit on Tuesday and cut its annual television sales forecast.

Sony said last month it had extricated itself from its LCD panel-making venture with Samsung Electronics, allowing it to source cheaper panels from the open market to try to keep pace with falling TV prices.

Panasonic is also in the process of consolidating five TV panel plants into two locations.

($1 = 76.20 yen)

(Additional reporting by Chang-Ran Kim and Hirotoshi Sugiyama; in Tokyo, and Sunayan Bhattacharjee in Bangalore; Editing by Ed Davies)