With the aim of providing consumers more flexibility in choosing a telecommunications service provider that suits their requirements, the Telecommunications Regulatory Authority's (TRA) much anticipated Number Portability service (the ability to move between operators and keep the same phone number) becomes a reality starting from tomorrow for mobile telephony (and for fixed telephony from 4 October 2011).
Number Portability is one of the initiatives that helps deliver the TRA vision of a communications environment that enriches the social and commercial fabric of the Kingdom of Bahrain, and enables innovative competition between service providers to improve quality of service as well as innovative service offerings and enhanced consumer experience.

Source: http://www.ameinfo.com/270731.html