Before Sprint’s board accepted Softbank’s $20.1 billion takeover offer, the carrier talked up potential deals with four other entities, according to documentation Sprint filed with the Securities and Exchange Commission late Monday.

Sprint didn’t reveal their identities, naming the companies W, X, Y, and Z, but Company W is most certainly MetroPCS, a carrier Sprint has been dancing around for more than a year. The proxy statement – which Sprint submitted ahead of a shareholder vote on the Softbank deal – said Sprint was in negotiations with Company W between December of 2011 and February of 2012 over a possible merger, but the talks fizzled out.

That fits in with reports back in February that Sprint and Metro were on the verge of closing an $8 billion deal, only to have it quashed by the Sprint board. What’s more, Company W frequently pops up throughout the filing as a Sprint acquisition target throughout the rest of 2012, the last reference to a possible deal being in late September. A few days later, T-Mobile and MetroPCS announced their own blockbuster merger plans. Sprint reportedly weighed countering T-Mobile’s bid, but decided against it.

Surmising the identities of the other three companies is a bit more difficult, though a good guess is that Company Z is Dish Network. Between May and September, Sprint was negotiating a potential spectrum partnership with Z, but nothing came of them because Z’s CEO was “focusing on certain regulatory issues.”

At the time, Dish and Sprint have long been rumored to be working out a network share, in which Sprint would host Dish’s new LTE network on its towers. Dish, however, didn’t get approval from the FCC to use its satellite airwaves for 4G until December. By that time Sprint’s relationship with Dish became hostile. Sprint forced Dish to make concessions on how it could use its spectrum, and Dish has been trying to block Sprint’s acquisition of Clearwire.

Companies X and Y remain bigger mysteries. According to the filing, in 2011 Sprint entertained a spectrum-for-equity deal with Company X, while between May and September of 2012, Sprint and Softbank were extensive discussions with company Y over a possible three-way tie-up.

Spectrum policy analyst Tim Farrar speculates that Company Y is T-Mobile USA. If that’s true, Softbank must have been considering quite the blockbuster deal, combining the third-and fourth-largest carriers in the U.S. T-Mobile and Sprint have been subject of merger rumors in the past, but such a deal would be loaded with complications. Not only would it be a tough sell to the regulators after AT&T-Mo, but the two companies use different 2G and 3G technologies, which would make integrating their operations a nightmare (Sprint is still learning its lessons from Nextel). Farrar said that Softbank probably soon realized that a T-Mobile-Sprint merger was infeasible, which is why it authorized Sprint to pursue Clearwire in December.

As for Company X, Farrar thinks its SpectrumCo, the cable-operator venture that sold its airwaves to Verizon last year. The timing makes sense. A few after Company X’s negotiations with Sprint ceased in 2011, the cable operators announced their blockbuster deal with Verizon.

Feature photo courtesy of Shutterstock user Paul Fleet; Sprint photo courtesy of Shutterstock user Susan Law Cain

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