Just months ago, AT&T announced its plan to acquire T-Mobile for a huge amount of $39 billion.  And now, the second-largest U.S. wireless carrier is offering a three-part, $5 billion worth of bonds to help repay the company’s maturing debt for this year.

AT&T sold $1.5 billion of 2.4 percent, five-year notes that yield 148 basis points more than similar-maturity Treasuries, $1.5 billion of 3.875 percent, 10-year debt at a spread of 160 basis points and $2 billion of 5.55 percent, 30-year bonds that pay 185 basis points more than benchmarks, according to data compiled by Bloomberg.

Proceeds may also be used for general corporate purposes, said a person familiar with the offering, who declined to be identified because the terms are private.

According to data provider Dealogic, the recent corporate offering by AT&T is the largest in the U.S. since Hewlett-Packard sold the same amount of bonds on May 25, and the carrier’s biggest since it sold $5.5 billion on January 2009.

Meanwhile, AT&T’s partnership with competitor T-Mobile is still opposed by consumers and politicians alike, while the FCC also reviews the company’s plan of acquiring Qualcomm’s spectrum.  Both moves by AT&T is due to its goals of expanding it service (merger with T-Mobile) and to improve its next generation wireless broadband efforts (deal with Qualcomm).

Through a redacted letter posted on the FCC website, AT&T reasons that the partnership with T-Mobile will deliver LTE network to rural America. With LTE, many Americans in rural areas will experience broadband connection that is almost equal to next generation wired broadband technologies.

As a sign of this effort, AT&T launched their first LTE devices—even though their LTE network is not yet fully up and ready.

The FCC can’t get its crosshairs off AT&T because of a possible monopoly, especially with the full extent of its redacted letter, which makes one think twice in giving AT&T the go ahead signal for the propose acquisition.

But AT&T spokeswoman Margaret Bowles was quick to defend by stating:

“While certain merger opponents refuse to acknowledge the clear benefits of AT&T’s LTE buildout commitment, they have never operated a network or run a business and they offer nothing but baseless speculation that conveniently ignores the facts.”

“The bottom line is that without this merger, AT&T could not make this expanded LTE commitment. Federal regulators have before them the facts that demonstrate that this merger will unleash billions of dollars in badly needed investment, creating many thousands of well-paying jobs, both of which are vitally needed given our weakened economy.”

If AT&T’s acquisition of T-Mobile goes through FCC’s net, 80 percent of the wireless market in the U.S. would focus in just two companies: AT&T/T-Mobile and Verizon Wireless.  How’s that sound for a return to the days of Ma Bell?

Let’s see who gets to there first.