A deal is all but done to combine the country’s third and fourth largest wireless networks, leaving T-Mobile U.S. Inc. chief executive John Legere in the catbird seat: He would control the combined assets of his company and Sprint Corp. in a mega-carrier merger that could be announced by the end of the month. News of the talks began circulating weeks ago, resulting in a rise in stock value at both carriers. Bloomberg News reports today that the merger is “likely to be announced when the wireless carriers report quarterly earnings at the end of October, according to people familiar with the matter.”

Among the details still being worked out, according to the report, is Sprint’s valuation in determining an exchange ratio for the all-stock deal. Sprint shares closed Thursday at $7.50  in New York, valuing the company at about $30 billion. Majority owner SoftBank Group Corp. reportedly would accept a valuation around Sprint’s market price.

The companies are also continuing discussions around non-cash items, including the location of the combined entity’s headquarters and appointments to the executive management team, according to the report. The wireless carriers are pursuing the deal to bulk up against industry giants AT&T Inc. and Verizon Communications Inc.

If approved by the Justice Department’s antitrust division, the merger would reduce the number of national wireless carriers to three from four.