(Yicai Global) Sept. 24 -- China Telecom, which staged the largest share sale on China's mainland this year, has fallen below the offering price despite the biggest shareholder's plan to increase its stake in the major mobile operator.

The telecoms firm's Shanghai-listed shares [SHA: 601728] fell as low as CNY4.43 (70 US dollar cents) intraday. The company floated its shares on the mainland on Aug. 20, pricing them at CNY4.53 apiece. The equity price had risen 35 percent on the first trading day.

Before this China Telecom went public in Hong Kong. Its Hong Kong-listed stock price [HKG: 0728] was flat at HKD2.63 (30 US dollar cents) in the afternoon, more than a half lower than its mainland equity price.

China Telecom issued 10.4 billion shares on the Shanghai Stock Exchange, and after a greenshoe option was exercised with a deadline of Sept. 20, the total financing rose to CNY54 billion (USD8.4 billion).

The controlling shareholder was anticipating the pricing advantage presented by the finished greenshoe option. China Telecom Group will raise its stake in the mobile operator by at least CNY4 billion (USD618.8 million) in the next 12 months, the Beijing-based company said in a statement on Sept. 21. The announcement was followed by an initial surge in stock price, but that turned into a decline on Sept. 23.

Editor: Dou Shicong, Emmi Laine, Xiao Yi