BlackBerry still holds a strong lead in the corporate world but is losing ground to other devices at smaller businesses, TNS found on Monday. Among all businesses, BlackBerry held 69 percent of the U.S. market, but saw its share drop sharply outside of big companies. Enterprises with 1,000 or more staffers were dominated by RIM's 81 percent share, but the iPhone now had 35 percent of small business, or twice as much as it had overall.

The gap was credited partly to hesitation from companies to use the iPhone due to Apple's policy limitations on apps and possible security concerns.

"Larger businesses tend to be slower to adopt new technologies and have greater investment in customized systems," TNS Senior VP Tom Buehrer said. "However, as employees increasingly demand support for multiple smartphone platforms and IT managers evaluate devices and mobile apps on the basis of delivering business value to their organizations, we expect companies to move away from a single device approach and offer more choices."

RIM has seen its overall share decline in recent months and is now starting to lose its absolute grip on certain companies' smartphone contracts, as companies like JPMorgan and UBS have been testing the option for employees to use iPhones instead. The device often covers at least basic security features such as remote wiping, pushing apps without iTunes and VPN support.

TNS is reporting overall smartphone users in the U.S. as 37% BlackBerry users, 28% iPhone users and 19% Android users. RIM needs some hot devices to start making a hit in the consumer and small business market. More so now that Android and iPhone have full Exchange sync while BlackBerry users have to pay for a BES plan and setup a BES Express server to get full Exchange sync.

With offices in more than 80 countries, TNS is a leader in custom research and analysis.