TOKYO (

TheStreet

) --

Toyota

(TM) - Get Report

, the world's biggest carmaker, swung to a fiscal first-quarter loss of 77.8 billion yen ($818.1 million) from net income a year earlier of 353.6 billion yen as vehicle sales fell and the appreciation of the yen hurt its results.

Toyota revised its forecast for the fiscal year ending in March 2010 to a loss of 450 billion yen, from a previous expectation of a loss of 550 billion yen, on net revenue of 16.8 trillion yen.

Net revenue in the first quarter ended in June fell 38.3% to 3.836 trillion yen.

Toyota said it sold 1.4 million vehicles in the quarter, down 785,00 from a year earlier. In North America, sales were 387,000, a decrease of 342,000 units.

"Although we were able to make certain improvements in fixed cost and cost reduction efforts, the decline in vehicle sales and the appreciation of the Japanese yen had a severe impact on our earnings," said Takahiko Ijichi, senior managing director, in a statement Tuesday.

It expects fiscal-year sales to rise to 6.6 million units from 6.5 million on improved vehicles sales in Japan.

-- Reported by Joseph Woelfel in New York

.