Trading in Bank of China shares has been suspended in Shanghai after the company did not comment on reports that it was planning big write-downs.
Bank of China is one of the largest in the country
"Bank of China failed to make a statement on an important event," the Shanghai stock exchange said.
According to media reports, the Bank of China may post a loss for 2007 because of its exposure to the US sub-prime mortgage sector.
The bank's Hong Kong-listed shares were not suspended and lost 8.6% on Tuesday.
The stock also fell 6.4% in Hong Kong on Monday on the media reports, but Bank of China, one of the largest in the country, said on Tuesday it was "not aware of any reasons for such movement".
'Expectation of a loss'
Meanwhile, the Shanghai Composite index followed the global trend on Tuesday and fell 7.2%, after dropping 5% on Monday, while Hong Kong shares experienced a record one-day fall of 8.7%.
Zhang Gang, an analyst at Southwest Securities, said that investors were "worried that the US credit crisis may spread into other countries".
"Financial stocks were hit the most, with the sentiment dampened on the expectation of a loss in the Bank of China annual report," said Shen Jun at Bank of China International.