If it's the middle of July, then it must be time for more merger rumors between Sprint and South Korea's SK Telecom.

CNBC got the ball rolling Monday when it reported that SK Telecom, which is South Korea's leader wireless carrier, was in talks to purchase Sprint. The article cited only anonymous sources, who insisted that no agreement was imminent and that any potential merger deal would at least be weeks away. Later in the day, Reuters reported that the talks between Sprint and SK Telecom did not revolve around a merger, but rather on collaborating technologically. Reuters' sources provided no details for what a technological collaboration might entail, although both carriers use the CDMA standard of wireless technology and both have invested in WiMAX technology for their 4G services.

This is not the first time Sprint and SK Telecom have been reported to be in merger or investment talks. Last November, Sprint nixed a $5 billion investment offer from SK Telecom and buyout firm Providence Equity Partners that also would have installed former Sprint chairman Tim Donahue as Sprint's CEO. SK Telecom and Providence Equity partners had proposed the investment to Sprint earlier in the month in a letter written to the telco in tandem to Donahue.

Last summer, a South Korean newspaper similarly reported that SK Telecom was preparing a bid for Sprint. At the time, a representative from SK Telecom's investor relations department called the report "a groundless rumor" and denied that the company had discussed funding a takeover of Sprint with various global equity funds. SK Telecom, which has about 22 million subscribers in South Korea, has also invested heavily in Chinese telecom firms, as the company spent roughly $1 billion on bonds last year in China United Telecommunications.

Sprint, which is the third-largest wireless carrier in the United States with 53 million subscribers, has also been rumored to be a takeover target for Deutsche Telekom, the German carrier whose T-Mobile USA unit is currently the fourth-largest wireless carrier in the United States with 28 million subscribers.