LightSquared Inc., facing a year-end deadline with partner Sprint Nextel Corp., pressed federal officials Tuesday to rule against critics who say the company's proposed national wireless-Internet network will interfere with global-positioning systems.

In a filing, LightSquared said the Federal Communications Commission should find that it has no obligation to pay for a fix for the GPS interference and that its opponents can no longer stand in the way of the company's commercial launch, slated for next year.

The filing comes less than two weeks before a Sprint deadline that LightSquared receive FCC clearance to operate its network as a condition of a 15-year fourth-generation spectrum and equipment sharing accord. LightSquared has said the Sprint accord will help it save $13 billion through the end of this decade.

LightSquared has been buffeted by criticism from lawmakers, the Defense Department and device manufacturers who say the company's airwaves can jam GPS signals. Trimble Navigation Ltd. and Deere & Co., which both make navigation devices, have countered that they previously operated with no interference to their equipment and shouldn't have to pay for any fixes.

The Reston, Va.-based company hopes to build out a 4G network to cover 260 million Americans by 2016 and compete with carriers such as Verizon Wireless and Clearwire Corp. in selling spectrum wholesale. LightSquared could inject needed capacity into the market after AT&T Inc. on Monday pulled out of its deal to buy out T-Mobile USA for $39 billion.

However it suffered a blow earlier this month when federal officials, such as the Department of Transportation and National Coordination Office for Spaced-Based Positioning, Navigation and Timing, said their testing had found LightSquared's network would knock out a "majority" of GPS devices.

LightSquared said in the filing that GPS device manufacturers had the opportunity to retrofit their receivers to prevent any interference. "It recently has become apparent that the commercial GPS industry has manufactured, and sold to unsuspecting customers, unlicensed and poorly designed GPS receivers," the company said in the filing.

Jeff Carlisle, LightSquared's executive vice president of regulatory affairs, said he hoped the petition would compel the FCC to expedite its process, though he conceded that it was unlikely there would be any ruling before early next year.

A Sprint spokesman said the Dec. 31 deadline for getting FCC clearance still stood, though the carrier has the option to extend it. "Both Sprint and LightSquared are pulling back on expenses and will stop new deployment design and implementation for LightSquared on the Sprint network," said the spokesman, Bill White.

LightSquared this summer agreed to use only a portion of its airwaves and lower the power of its cell towers to help mitigate GPS interference. It has agreements with Best Buy Co., Leap Wireless International Inc. and others to provide 4G mobile broadband service after it gets FCC approval.

The company also faces an uncertain future over how it will fund its operations. LightSquared officials have said it has enough cash to operate until after an FCC ruling, though the start-up—funded largely by billionaire Philip Falcone's Harbinger Capital Partners hedge fund—will need to find an additional $3.5 billion to be cash-flow positive over the next two years.

Dish Network Corp., like LightSquared before it, is seeking FCC approval to use satellite airwaves for a terrestrial network.

Write to Greg Bensinger at