U.S. cellular operators are headed toward a loss of $3.3 billion a year by 2011 because of fixed-mobile convergence (FMC), according to an Indian research firm.

FMC, which promises a single portable communications device that can work across fixed wireline and mobile wireless networks, is being evaluated cautiously by cellular operators because of uncertainty over the technology’s impact on their business, according to market researcher iLocus. The firm claims to have that affect pegged in a new report that estimates revenue losses/gain for cellular operators because of FMC.

Cellular operators in the United States need to gain a market share of 61% in FMC by the year 2011 to balance the impact of FMC on their revenue streams, iLocus says. United Kingdom cellular operators will have to gain a market share of 63% by the year 2011 to balance the impact of FMC on their revenue streams, according to the report.

In a similar analysis for the U.K., cellular operators there stand to lose $1.3 billion a year by 2011 because of FMC, according to iLocus. The firm’s report analyzes the impact of FMC, which is being tested by 250 service providers worldwide, in 12 countries.