SABMiller and Molson Coors Brewing Company have officially launched their MillerCoors joint venture operation in the US and Puerto Rico, writes Ewan Turney . SABMiller chief executive Graham Mackay hailed the launch as an "historic day in the American beer business". Leo Kiely, chief executive of MillerCoors, said: “MillerCoors will be entrepreneurial, with the ability to operate with speed and agility in the marketplace, backed by the powerful combined resources of two exceptionally successful companies. "We will drive profitable growth and bring new energy to the U.S. beer industry. "Our focus now is to deliver on the $500m in identified annualised cost synergies by improving sourcing across our eight major breweries, building a streamlined organization and leveraging the scale of the new company. "Our talented people are experienced and passionate about this business and – importantly – are determined to win.”