Samsung Electronics Co.’s Galaxy S4 smartphone, the main challenger to Apple Inc.’s iPhone, will go on sale next week at U.S. carriers, including T-Mobile USA and Sprint Nextel.

Seven U.S. carriers and seven retailers will be selling the Galaxy S4, Samsung said in a statement.

T-Mobile aims to be first with the device, with an April 24 release date.

Sprint will offer the phone on April 27.

Verizon Wireless, the largest U.S. carrier, said today that it hasn’t set a date yet.

AT&T Inc. has started taking advance orders and says phones will ship starting April 30. It’s charging $200 for the base model, with 16 gigabytes of memory, under a two-year contract.

Staples says it will start selling the AT&T model on April 26.

Sprint in-store sales start April 27. It charges $250 for the base model, or $150 if the buyer is coming over from another carrier.

T-Mobile USA starts taking advance orders next Wednesday, and in-store sales start May 1. It’s charging $150 up front and $20 per month for two years under its new installment plans. Those plans replace two-year service contracts that most carriers require. T-Mobile has abandoned them in favor of cheaper month-to-month plans.

Smaller carriers U.S. Cellular, Leap Wireless’ Cricket and C Spire will also sell the phone.

Wal-Mart Stores Inc., the world’s largest retailer, plans to offer the device for $168 with a two-year contract from AT&T.

The Galaxy S4, unveiled last month at a lavish event in New York, represents the biggest threat to the iPhone’s lead in the U.S. market.

The phone sports a larger screen, faster processor and higher-resolution camera, putting pressure on Apple to match those capabilities.

The next version of the iPhone isn’t expected until later this year.