Sony Corp and rival Panasonic Corp are set to report a slump in quarterly earnings and may cut full-year forecasts after being hit by yen strength, Thai floods and consumer gloom in Europe during the vital pre-Christmas period.

Both companies saw their debt ratings downgraded by Moody's Investor Services last week, as their TV divisions continue to bleed red ink despite restructuring efforts.

Sony, which reports on February 2, is expected to barely break even for the normally lucrative October-December quarter. Operating profit is seen shriveling 94 percent to 8.8 billion yen ($114.3 million), based on an average estimate from 6 analysts polled by Thomson Reuters I/B/E/S.

That would be its worst third-quarter performance since the 2008 financial crisis. By contrast, Samsung Electronics posted a record quarterly profit this month on growing smartphone sales.

During the quarter, Europe's debt crisis battered consumer confidence there while U.S. holiday spending on traditional electronic goods such as TVs and cameras -- which Japanese makers are more reliant on -- fell, as TV prices slid and as consumers splurged more money on tablets.

Japan's TV makers have fallen behind their South Korean counterparts, partly hobbled by unfavorable exchange rates and their failure to bite the bullet on necessary investments.

They have not made the right massive investments in panel manufacturing at the right time. If you do this half-heartedly, it ties your hands and has the opposite of the desired effect, said Nobuo Kurahashi, an analyst at Mizuho Investors Securities.

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

That was seen as a necessary step to return its ailing TV business to profit after what is expected to be its eighth straight annual loss in the year to March.

But TV prices continue to slide. A 40-inch flat panel TV cost an average 68,200 yen in Japan in December, down nearly 40 percent from a year earlier, according to research firm BCN.

The maker of everything from PlayStation games consoles to The Smurfs movie, Sony has touted its mobile phone business as a way of integrating its online content offerings across devices to better compete with Apple.

But Sony Ericsson posted an unexpected 247 million euro ($322.3 million) loss for the final quarter, underscoring the hurdles Sony faces in smartphones too.

For the full-year to end-March, the market consensus from 19 analysts is for Sony to post an operating profit of just 8 billion yen, below the company's forecast of 20 billion yen.

Panasonic, which reports on February 3, is expected to see a 41 percent fall in quarterly operating profit to 56.2 billion yen, hurt by losses in its TV division, lower chip earnings and a weak performance from its Sanyo unit.

Analysts expect a full-year operating profit of 124 billion yen, less than the company's forecast of 130 billion yen, and the firm may cut its guidance for the second time.

The company is already forecasting a 420 billion yen net loss for the year, its worst in a decade, as it hives off overlapping businesses after buying out subsidiaries including Sanyo and accelerates restructuring in its TV division.

The best performer among domestic TV players may well be Sharp Corp, whose move to focus on premium large screen televisions, capitalizing on its 10th generation LCD panel plant, may protect it from a slide in profit, some analysts say.

Games maker Nintendo Co Ltd, which kicks off the sector's earnings announcements on January 26, is expected to see a 50 percent slide in quarterly profit after slashing the price of its 3DS handheld games gadget to boost sales.

Shares in Sony have fallen by almost half since the beginning of the financial year, while Panasonic has fallen about 40 percent, compared with a decline of 10 percent for the Nikkei.

($1 = 77.1200 Japanese yen) ($1 = 0.7665 euros)

(Editing by Edwina Gibbs)

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