The launch of Apple Inc.'s iPhone 4S has become the most successful iPhone release ever for the wireless carrier AT&T.

AT&T received more than 200,000 iPhone 4S preorders in the first 12 hours after opening the preorder period for the much-awaited smartphone.

The huge demand was not seen with AT&T only; other service providers such as Verizon Wireless and Sprint also received great response from customers preordering the device.

Our systems were humming very strongly since 3 a.m., [and executives were] pleased with the sales and the ordering process, The Wall Street Journal quoted a Verizon Wireless representative as saying.

The new iPhone with its cool camera and powerful microprocessor is supposed to break old sales records for Apple devices. The company holds a record of selling 1.7 million iPhones in three days in June of last year.

Piper Jaffray analyst Gene Munster estimated Apple would sell 25 million handsets in the current quarter, the Journal reported.

With the steep rise in demand for the iPhone 4S, Apple has indicated the shipping date of the phone would be one to two weeks after each order. Earlier, the company's Web site had pegged it as Oct. 14.