Shareholders of the Hong Kong-listed firm last week approved a buy-out offer that would see the firm privatized.
The company said earlier this month it planned to de-list from the Hong Kong stock exchange on Sept. 20.
Wang said both options were on the table for the planned Shanghai re-listing. Approval for an IPO could take two or three years, while a backdoor listing would require more than a year, he added.
Mainland-listed firms typically command higher valuations than those traded in Hong Kong, helped by a large pool of retail investors.
But Wang said the "core problem" that triggered the de-listing plan was not the low valuation of the company's Hong Kong shares, but the lack of liquidity.
"We only listed 14 percent of the company in Hong Kong, which means 86 percent of shares are neither liquid nor could be pledged as collateral," Wang said. "That's not a real listed company."
This story was provided by Reuters.