China MediaExpress Inc on Monday termed the research reports calling the company's financial results into question as misleading, and said its financial statements are backed by well known auditors.

Shares of the China-based advertising company were up 6 percent at $14.68 in morning trading on Nasdaq.

The stock lost nearly 50 percent of its value in the first four days of last week when two separate reports by online brokerages raised concerns on the credibility of the company's operations and its reported 2009 revenue.

Chief Executive Zheng Cheng said the reports are the handiwork of short sellers.

We have every reason to believe that each of these 'researchers' is actually a short seller, and each stands to make money when they succeed in driving down the price of our stock, he said in a statement.

Online brokerage Muddy Waters Research called into question the company's reported revenue and scale of operations close on the heels of another online broker Citron Research's similar allegations.

The company also said its board has authorized engagement of outside counsel and other consultants for advise on countermeasures against the two reports.