Sprint has landed a $1 billion credit facility that will provide extra cash for its network upgrade project.

The money will be used to buy equipment from Ericsson, one of Sprint's three vendors for the overhaul.

Deutsche Bank and a group of other banks are providing the loan, due in March 2017. Separately, Sprint announced it was paying off $1 billion of debt maturities due next year.

Sprint has raised about $7 billion in debt since late last year to meet a funding gap caused by its $15.5 billion gamble on the iPhone and its costly infrastructure project.

The investments are at the center of Sprint’s efforts to revitalize its business. The network modernization will replace Sprint’s iDEN network with a CDMA-based push-to-talk service and allow Sprint to roll out LTE.

Sprint already has come out with its first LTE devices. Its LTE network is slated for a mid-year launch in six major cities, including Houston, Dallas, San Antonio, Atlanta, Kansas City and Baltimore.

It raised $4 billion in debt last November and tapped the capital markets for another $2 billion in February to help pay off some of its debt, pay for its network build and provide potential funding for Clearwire.

The debt is at the high range of the amount of money Sprint told investors last fall it would have to raise to keep its business running through 2013, when it estimated it would need between $5 billion and $7 billion to address its funding requirements.

Sprint's stock has taken a beating over the past year, losing about half of its value from June 2011. Despite improving some of its customer metrics and selling 1.5 million iPhones, the company's losses grew to $836 million in the first quarter, from $439 million the previous year.