Sprint Nextel (S) has reportedly held discussions about acquiring Deutsche Telekom’s T-Mobile USA in a deal that would marry the third- and fourth-largest U.S. wireless providers.

According to Bloomberg News, talks between Sprint and the German telecom have been on and off, but a deal would likely give Deutsche Telekom a major stake in the combined entity. The companies haven’t been able to agree on a price tag of T-Mobile USA, the news agency reported.

The report sent shares of Sprint jumping 4.5% Tuesday.

The negotiations have included discussion of Deutsche Telekom owning about 50% of a combined T-Mobile USA-Sprint, Bloomberg reported.

Sprint and T-Mobile USA rank third and fourth in the U.S., trailing Verizon’s (VZ) Verizon Wireless and AT&T (T).

T-Mobile, which posted a decline in fourth-quarter profits, disclosed a loss of about 56,000 customers in 2010.

As an alternative to a deal with Sprint, T-Mobile USA is also reportedly considering buying wireless spectrum from Clearwire (CLWR), which is majority owned by Sprint. Shares of Clearwire gained 4.64% to $5.17 in early trading amid the reports.

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