Toyota Motor Corp's <7203.T> operating loss could balloon to over 500 billion yen ($5 billion) in the year to March 2010, as the global economic crisis hits car sales, the Nikkei business daily said on Sunday without citing sources.

Sales of automobiles could tumble to about 6.5 million units during the current year, falling 7 million units for the first time in six years, Nikkei said.

A survey of 19 brokerages by Reuters Estimates has operating loss at the world's biggest automaker expanding to a median 550 billion yen in the current year, from an estimated 450 billion yen in the year ended last month.

Analysts say the outcome will depend on the exchange rate, the global vehicle demand and how much Toyota will be able to reduce its costs.

(Reporting by Chang-Ran Kim, writing by Miho Yoshikawa; Editing by Kazunori Takada)