TOKYO, Nov 6 (Reuters) - Toyota Motor Corp's operating profit will plunge to an eight-year low below $10 billion this year as the financial crisis carves through the sector, a paper said, sending the automaker's shares sliding 8.9 percent.

Auto sales have dived in the United States, Japan, Europe and emerging markets, thanks to tightening credit and a looming recession from the financial crisis, and the Tokyo Shimbun said this would more than halve Toyota's operating profit for 2008/09.

Toyota, the No.1 automaker and until recently the envy of the industry with eight straight years of profit growth, has put factories on hold, let go temporary staff and offered unprecedented incentives to buyers as sales slide.

If Toyota confirms the bleak forecast when it reports quarterly results at 3 p.m. (0600 GMT), it would be well below an average operating profit projection of 1.34 trillion yen from a poll of 17 brokerages.

The company reported a record 2.27 trillion yen profit last year, but the industry's woes have seen its shares slide by a third this year, to 3,870 on Thursday - in line with a similar fall in Tokyo's transport sector subindex. Tokyo's benchmark Nikkei share average fell 5.7 percent on Thursday.

The Tokyo Shimbun reported last month that Toyota's operating profit would be 1-1.2 trillion yen, but said growing woes in the sector would mean a further downgrade to below 1 trillion yen ($10 billion). That would not be big surprise, said Kenichi Hirano, operating officer at Tachibana Securities.

"Even if Toyota's operating profit were to miss the 1 trillion yen mark, that alone wouldn't accelerate dumping of its shares at this point," he said. U.S. BLUES Toyota, the maker of the Camry sedan, Prius gas-electric hybrid and Tundra pickup truck, has previously forecast a 30 percent fall in operating profit to 1.6 trillion yen this year.

Toyota's U.S. sales have fallen 12 percent so far this year, prompting the top Japanese automaker to lower its forecast there this week -the second cut in four months. Its October U.S. sales slid 26 percent from last year, while
its non-minicar sales in Japan fell 13 percent.

But others are faring even worse, prompting talk of mergers between Detroit's General Motors Corp and Chrysler LLC as sales plunge and they face deep losses.

The impact of the global credit crisis has spread to emerging markets such as China and India, throwing a wrench in automakers' plans to seek strong growth there to offset slumping sales in the big U.S. and European markets.

Toyota's announcement will complete a brutal earnings season for Japanese carmakers. Of the eight, only Fuji Heavy Industries Ltd did not lower its annual forecasts.

Nissan Motor Co shocked investors last week by more than halving its operating profit forecast. Toyota has lost $77 billion in market capitalisation this year, ceding its long-held post as the world's most valuable carmaker to Volkswagen, which has gained on Porsche's plan to buy more than three-quarters of the German car maker.