Carson Block, the prominent short seller and founder of Muddy Waters Capital LLC, targeted a Japanese firm for the first time with a negative report on motor-maker Nidec Corp.

Muddy Waters is short the Kyoto-based company and sees its stock falling as much as 52 percent from Monday¡¯s close, it wrote in a 53-page short-biased report. Nidec consistently misses sales and profit targets and uses ¡°highly aggressive accounting¡± to boost reported profitability, Muddy Waters wrote. A spokesman for Nidec said he had no immediate comment. Its shares dropped as much as 5.9 percent in morning trading Tuesday before paring declines.

¡°In our view this company is not well-governed,¡± Block said in a phone interview from San Francisco. ¡°It uses acquisitions to try to cover up a lack of organic growth in its business.¡±