When John Stephens, AT&T Corp.'s controller for the past 10 years, takes over as CFO on June 1 he will bring to the job a decade of experience managing business planning, financial reporting, and accounting policy. He had previously served as vice president, taxes.The company, though, is hoping that not much will change in finance from its acquisition-powered past under its retiring CFO, Rick Lindner."Rick and John have worked together closely for more than 15 years, and we expect a seamless transition." Randall Stephenson, AT&T chairman and chief executive officer, said in the company's press release.The 56-year-old Lindner is credited by AT&T with helping integrate its acquisitions over a 19-year career that developed it from a regional utility. That M&A included the January 2007 purchase of BellSouth Corp. for more than $80 billion, described by Bloomberg News as the industry's biggest worldwide deal, Before coming to AT&T, Lindner had served as finance chief of Cingular Wireless, the mobile carrier that is now part of AT&T."He certainly took a leadership role in transforming AT&T," said Michael Nelson, an analyst at Mizuho Securities USA Inc., told Bloomberg. The New York-based analyst rates AT&T shares "outperform," and doesn't own any. "The company made significant acquisitions, rolling up the sector to become the dominant player it is today."While AT&T is the largest U.S. phone company, it's second to Verizon Wireless in mobile subscribers. Verizon gained the top spot after its parent, Verizon Communications Inc., bought Alltel Corp. in January 2009. At the same time, AT&T customers began complaining about dropped calls and other network problems.Revenue from home-phone lines, AT&T's traditional business, is declining as more customers move to mobile phones and digital service. Sales and net income declined in 2009 amid the global economic crisis.The company rebounded in 2010, benefiting from surging demand for smartphones, including Apple Inc.'s iPhone. Revenue grew 1.4 percent to $124.3 billion last year.AT&T fell 21 cents to $27.92 in New York Stock Exchange composite trading Friday, and has declined 5% this year.