News Corporation reported a surge in first-quarter earnings yesterday, driven by stronger advertising and subscriber growth at its cable news channel and regional sports networks. The media giant reported operating income of $548 million, up 51 percent from $362 million in the year-ago period, when Sept. 11 hurt most media companies' earnings. Revenue grew 12 percent to $3.8 billion. Net profit was $162 million, or 12 cents per share, considerably better than the 10 cents expected by analysts. Among News Corp.'s properties are Fox Entertainment, Twentieth Century Fox film studios and satellite television assets. News Corp. also owns The Post. The earnings report underscored News Corp.'s strength compared with some of its troubled rivals, such as AOL Time Warner and Vivendi.