Dismissing them as based on speculation, Softbank Corp. declined comment on media reports Thursday that the firm is considering buying a majority stake in Sprint Nextel Corp., the third-largest U.S.-based telecom carrier.

"(Those reports) are not based on an announcement from our company. We have no comment," Softbank said Thursday evening in a written statement.

Earlier Thursday, major news outlets, including NHK and the Nikkei newspaper, reported Softbank is considering buying out the U.S. carrier. According to Kyodo News, Japan's third-largest carrier is aiming to acquire the third-largest U.S. carrier for more than ¥1 trillion.

Kyodo also said Softbank appears to want to cut costs by jointly procuring handsets and equipment with Sprint.

The Nikkei Shimbun reported that Softbank is seeking to buy two-thirds of Sprint's shares in a deal worth as much as ¥2 trillion.

Sprint has about 56 million subscribers, while Softbank has about 39 million.

The strong yen appears to have helped induce Softbank to consider the acquisition, Kyodo said.

This is not the first time Softbank has shaken up the industry with an M&A deal.

Just last week it moved to acquire eAccess Ltd., Japan's fourth-largest carrier, for about ¥180 billion to reinforce its networks, which are handling increased traffic due to the growth in smartphone use.

Softbank entered the cellphone business in 2006 through the acquisition, for ¥1.75 trillion, of the Japanese arm of Britain-based telecom giant Vodafone Group.

Softbank CEO Masayoshi Son has repeatedly said Softbank's ultimate goal is to top NTT DoCoMo Inc., Japan's largest carrier.

As a provider of Apple Inc.'s popular iPhone, Softbank has posted record operating profits for seven consecutive years.