WASHINGTON, March 24 (Reuters) - Internet search engine Google Inc gave U.S. regulators on Monday a proposal for allowing the airwaves between broadcast channels to be used for mobile broadband services.

In comments filed with the Federal Communications Commission, Google said it would propose an enhanced system to prevent wireless devices operating in the so-called "white space" from interfering with adjacent television channels and wireless microphones.

Google said the enhancements "will eliminate any remaining legitimate concerns about the merits of using the white space for unlicensed personal/portable devices."

The FCC currently is testing equipment to see if they can make use of the white space spectrum without interfering with television broadcasts.

The filing comes less than two weeks after Microsoft co-founder Bill Gates urged the FCC to free up the white space spectrum so it could be used to expand access of wireless broadband service using Wi-Fi technology.

Google and Microsoft are part of a coalition of technology companies that has been lobbying the FCC to allow unlicensed use of white space spectrum.

The group also includes Dell, Intel Corp, Hewlett-Packard Co and the north American unit of Philips Electronics.

However, the idea is opposed by U.S. broadcasters and makers of wireless microphones, who fear the devices would cause interference.

A proposal being studied by the FCC would create two categories of users for the airwaves: one for low-power, personal, portable devices, and a second group for fixed commercial operations.

The proposal would require that the devices include technology to identify unused spectrum and avoid interference.

(Reporting by Peter Kaplan; editing by Tim Dobbyn)

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