The groups argued that the FCC should be able to set aside spectrum for unlicensed use.
A congressional conference committee is expected to include provisions that would restructure how the country uses its airwaves as part of a package to extend payroll tax cuts.
The spectrum provisions would authorize the FCC to auction airwaves that currently belong to television broadcasters, splitting some of the revenue with the stations that choose to participate.
The spectrum is potentially worth billions of dollars to wireless carriers, which are struggling to meet the growing data demands of smartphones and tablet computers.
The auction proceeds would help offset the cost of extending the tax cuts.
The Republican version of the legislation, which the House approved last year, would restrict the FCC's ability to impose conditions on the companies that buy the spectrum, and would prohibit the FCC from designating the spectrum it reclaims from broadcasters for unlicensed use. Technologies such as Wi-Fi, Bluetooth and remote controls transmit their signals over unlicensed spectrum bands.
Microsoft and Google in particular are lobbying Congress to set aside more airwaves for unlicensed use. They argue more unlicensed spectrum will lead to innovation and economic growth.
But the bill's sponsor, Rep. Greg Walden (R-Ore.), argues the government should not pay to reclaim airwaves that it will then give away for free in the form of unlicensed spectrum.
His bill would not affect any spectrum that is already reserved for unlicensed use.
"Unlicensed spectrum has an important role to play, and we have worked hard to find the right balance on a policy that protects taxpayers and promotes innovation," Rep. Walden said in a statement last week. "There is currently more unlicensed spectrum than there is licensed spectrum for wireless broadband use."
Walden, who is chairman of the Energy and Commerce's telecom subcommittee, said his spectrum bill "simply says that the FCC cannot spend taxpayer funds to clear additional spectrum and then give away that billions of dollars worth of spectrum. Taxpayers deserve a return on their investment."
In Monday's letter, the companies pointed to a British regulator which is moving forward on a plan to allow for unlicensed spectrum in the television band.
"The rest of the world is not waiting, and nor should we," the companies wrote.
Dozens of lawmakers, led by Reps. Anna Eshoo (D-Calif.) and Darrell Issa (R-Calif.), urged the conference committee last week to not prevent the FCC from setting aside unlicensed spectrum.
--Updated at 5:21 p.m.