Verizon Communications Inc. said Tuesday it agreed to buy AOL Inc. for $50 a share, or about $4.4 billion. Tim Armstrong, AOL chairman and CEO, will continue to lead AOL operations after closing. AOL’s key assets include its subscription business as well as content brands like The Huffington Post, TechCrunch and Engagdet. LionTree Advisors, Guggenheim Partners and Weil, Gotshal & Manges advised Verizon. Allen & Company LLC and Wachtell, Lipton, Rosen & Katz provided advice to AOL.