Walgreens said on Tuesday that it will buy rival Rite Aid in a $17.2 billion deal that would whittle the nation's one-time mom-and-pop drug-store industry into two massive chains.<br />The deal would combine the second and third largest drug-store operators, and if it gets regulatory approval intensify the already fierce competition between Walgreens and CVS Health.<br />Walgreens Boots Alliance, which operates the namesake drug store chain, said it is paying $9 per share in cash in a valuation that includes the assumption of debt.<br />That reflects a 48% premium above Rite Aid's value at the close of trading Monday.<br />Walgreens said Rite Aid would keep its brand name for now.<br />The company expects to save more than $1 billion in "synergies," which could come in the form of combined purchasing power and cost cuts.