Toshiba Corp can't get past its accounting problems.

The Japanese company, which paid a record fine a year ago for its bookkeeping practices, warned that it may now have to take another charge of several billion dollars related to an acquisition made by US unit Westinghouse Electric.

The company's shares fell 12 percent to 392 yen ($3.33) at the close in Tokyo on Tuesday, the biggest decline since December 2015, after earlier reports that it may book a loss of as much as 500 billion yen. Toshiba issued a statement after the market closed, saying that while the final writedown was yet to be determined, it would affect earnings.

The loss is related to a dispute over the value of an acquisition by Westinghouse of a nuclear construction company called CB&I Stone & Webster Inc. The Nikkei newspaper said the writedown would come to about 100 billion yen, while Japanese broadcaster NHK said the charge may total as much as 500 billion yen. The Tokyo-based company booked a loss of 460 billion yen last year.

"Assuming the article to be accurate, we would expect Toshiba's weak financial standing to be damaged further," said Takeshi Tanaka, an analyst at Mizuho Securities Co.

Toshiba didn't elaborate further in Tuesday's statement to the Tokyo Stock Exchange.

Bloomberg