Wireless companies Sprint and T-Mobile US have informed the Federal Communications Commission that they will formally file an application asking for approval to merge on Monday, according to a document seen by Reuters.

The document, which was filed to the FCC on Thursday, also requests a protective order that would shield sensitive corporate information from public view.

The two companies, which are the third- and fourth-largest wireless carries, agreed to a $26 billion all-stock deal in April that they said would create thousands of jobs and help the United States beat China to creating the next generation mobile network.

Two areas of potential regulatory concern focus on the companies' large market share for prepaid and wholesale customers.

Neither Sprint nor T-Mobile immediately responded to a request for comment.