Wal-Mart Stores Inc said on Wednesday it will begin offering two new no-contract wireless service plans at its U.S. discount stores, including a $30 prepaid plan that includes 1,000 minutes.

Wal-Mart said the Straight Talk no-contract wireless offerings are an exclusive service developed with TracFone Wireless Inc, the U.S. unit of Mexican cell-phone giant America Movil , owned by billionaire Carlos Slim.

Wal-Mart was rolling out the plan nationwide after conducting a pilot program in 234 stores.

The new plans will likely put pressure on rivals Leap Wireless International Inc , MetroPCS
and Sprint Nextel unit Boost, as these companies all offer unlimited calling plans for around $50 a month.

(Reporting by Nicole Maestri, editing by Maureen Bavdek)