East meets West, as Washington, DC-based Arnold & Porter is set to acquire San Francisco's Howard Rice Nemerovski Canaday Falk & Rabkin.  Primarily known as an inside-the-beltway firm, Arnold & Porter has prominent securities and antitrust practices.  Among its top attorneys, Peter Zimroth represents the AIG Credit Facility Trust - which holds the taxpayers' 80% share of AIG - and William Baer, who heads its antitrust practice and is a former director of the FTC's Bureau of Competition. Howard Rice, with about 80 attorneys, has become somewhat of a rarity.  It's been a midsize firm that has tried to remain competitive with international firms that have been increasingly dominating the scene.  Orrick, Herrington & Sutcliffe and Morrison & Foerster, each with some 1,000 attorneys, are the biggest SF-based firms.  Howard Rice's clients include The Clorox Co, Google Inc, the Charles Schwab Corp, and the NFL's Oakland Raiders. The combined firm will have 160 attorneys based in San Francisco, Silicon Valley and Los Angeles, and about 800 across the U.S. and Europe.  No attorneys are expected to lose their jobs, but, effective 1/1/12, 27 support staff positions will be cut.  The firm will retain the Arnold & Porter name.  [Reuters 12/6/11]