Argentina's President Cristina Kirchner said Wednesday that number portability will be available nationwide on March 30.

Last week, Argentina's quartet of wireless carriers started testing the portability system, which allows consumers to keep their phone number when changing service providers.

Argentina is following in the footsteps of Brazil, Chile and Mexico in adopting number portability.

Mobile operators have already started bombarding consumers with full-page newspaper ads and television commercials touting their products and calling plans.

Franco Bertone, chief executive of Telecom Argentina SA (TEO, TECO2.BA), recently said portability will do more for customers than it will for companies.

"People have started thinking of their phone number as something that they own" and the industry has to adapt to that, Bertone said at a press conference last month.

But portability isn't expected to cause a major shakeup in an industry that has just over 55 million subscribers. In other countries that have portability, just 3% to 5% of customers switch carriers a year, according to wireless industry executives.

Argentina boasts one of the highest mobile phone ownership rates in the world thanks in part to Argentines' adoration of technological gadgets.

In 2010, Argentina had about 142 mobile phones for every 100 residents, according to the International Telecommunications Union. By comparison, Brazil had 104 per 100 residents, Japan 95 and the U.S. 90.

Claro, a unit of Mexico's America Movil SAB (AMOV, AMX, AMX.MX), is the largest of Argentina's four mobile companies with about 19 million customers.

Telecom Argentina SA reported 18.2 million wireless subscribers at the end of December, followed by Spain's Telefonica SA (TEF, TEF.MC) with 16.7 million and U.S.-based NII Holdings Inc's (NIHD) Nextel Argentina unit with 1.5 million.

Industry executives say competition is already cutthroat, but portability will force companies to offer better deals and service.

-By Ken Parks, Dow Jones Newswires; 54-11-4103-6740; ken.parks@dowjones.com