Nearly 40 developers and game publishers are building software for the PlayStation Move, said Sony.

Sony has unveiled a motion controller for the PlayStation 3, offering gamers its answer to the Nintendo Wii.

The consumer electronics company formally introduced the PlayStation Move Tuesday at the Game Developers Conference in San Francisco. Sony first announced its plans for a controller last June, but did not offer many details.

The Move is a rectangular device curved on the sides to fit comfortably in the hand. It also has a glowing ball at the end that contains superiority used in tracking a player's motions.

The Move is scheduled to be available in the fall in a starter kit that will sell for less than $100. The kit includes the controller, an "eye" camera required for the PS 3 to track motion. Sony also plans to offer a premium bundle, but details were not disclosed.

Sony plans to release a sub-controller at the same time as the Move to enhance game play. The device "pairs with the motion controller and comes with an analog stick and directional buttons that allow users to easily control the game when moving characters or choosing a direction," the company said. Exactly how the two devices will be used together is not clear.