Sprint Chairman Masayoshi Son approached Berkshire Hathaway Chairman Warren Buffett to discuss a deal with the wireless-service provider, according to a report on Friday by The Wall Street Journal’s Ryan Knutson and Shalini Ramachandran. Son also met with John Malone, the cable mogul, at the Allen & Co. annual conference in Sun Valley, Idaho, the report said. The Journal reported that details of the potential deal were unclear but that it could be an investment of over $10 billion in Sprint from Berkshire Hathaway. Sprint shares gained as much as 4% after the news. Amid fierce competition and price cuts among the largest telecoms companies, the chief financial officer of T-Mobile has said the company would benefit from a merger with Sprint. Sprint’s controlling shareholder was gearing up for deal talks with T-Mobile’s top shareholder, Deutsche Telekom AG, Reuters reported in May. Berkshire Hathaway has announced big investments in recent months. The conglomerate’s energy business agreed on July 7 to acquire Energy Future Holdings for $9 billion in cash. And in June, Berkshire granted a credit line of $2 billion Canadian dollars ($1.5 billion) to Home Capital, the embattled Canadian mortgage company.