While SK Telecom has officially denied it would take a controlling stake in any US mobile carrier, it is still looking at business opportunities here.

The Korean telecommunications firm made the comments in a filing with the Korean stock exchange on Thursday. Reports had earlier suggested that it was considering buying out Sprint Nextel.

Financial analysts had discounted the rumors, which had first appeared on CNBC, saying the company would not have been able to afford Sprint. Investors did not respond positively to the news, driving the price of the stock down.

A non-denial of any partnership seems to suggest that subsequent reports of a sharing of technology between the two companies may be correct. Some of the collaborative work may revolve around developing cell phone applications, and could quite possibly extend into WiMAX as well.

SK has denied commenting further on what the company may be considering in lieu of a buyout. The company had received a request from the Korean stock exchange to clarify its position after the rumors broke.

Helio was the Korean telco's last attempt at breaking into the US market, but the service never took off and lost a good deal of money. SK ended up selling the unit to Virgin Mobile for $39 million last month, but took a 20 percent stake in the merged company.