The new company, named Anheuser-Busch InBev, will be headed by InBev CEO Carlos Brito and will be headquartered at Leuven, Belgium.
InBev promises to keep Anheuser-Busch's St. Louis base as the company's North American headquarters but the takeover ends 150 years of family rule at Anheuser-Busch. Anheuser-Busch President and CEO August A. Busch IV joins the new company's board as a non-executive director.
Anheuser-Busch shares stopped trading Monday and will now be swapped for $70 each in cash.
The Belgian-Brazilian takeover of Anheuser-Busch comes after a bitter takeover battle turned sweeter with a higher offer in July, despite protests in St. Louis that saw politicians criticize the deal and Web sites call for Bud to be saved from 'the waffle guys.'
Anheuser-Busch provides half of America's beer but it has not managed to expand around the world as fast as InBev - a Belgian-Brazilian hybrid that owns hundreds of local brands but few real stars.
Anheuser-Busch owns several properties in Virginia in the Williamsburg area. In addition to a brewery in Williamsburg, the company's subsidiaries own the Busch Gardens theme park, the Kingsmill Resort and Spa, and the Water Country USA water park.
InBev has promised to keep all 12 North American breweries open as long as the company faces no new U.S. taxes. Anheuser-Busch already plans to shed 1,185 positions - mostly by offering early retirement and not filling vacancies.
The company did not mention a dispute with Mexico's largest brewer Grupo Modelo - which was 50-percent owned by Anheuser-Busch. Grupo Modelo filed a notice of arbitration against Anheuser-Busch last month, saying the takeover violated their investment agreement and its right of consent to enter into a partnership with InBev.
Taking over Anheuser-Busch gives InBev a jewel of a brand in Budweiser - the world's top selling beer - which it promises to sell more widely by pushing into emerging economies in Asia, Latin America and eastern Europe. It will sell a fifth of all beer in both Russia and China.
This will help generate growth as beer sales decline in North America and Europe where drinkers are cutting back and turning to wine and other drinks.
The new company leapfrogs SABMiller as top brewer and becomes one of the world's top five consumer goods companies.
Brito said the combination had created "a stronger, more competitive global company with a leading international brand portfolio and distribution network, and great potential for growth all over the world."
InBev said it now had all the regulatory clearances it needed for the deal.
China approved the takeover on Tuesday but barred the company from increasing existing stakes in Chinese brewers. It said it was necessary to prevent Anheuser-Busch InBev becoming a monopoly in the country.
This curbs future growth in the world's most populous nation. It caps Anheuser-Busch's 27-percent stake in Tsingtao Beer Ltd. and InBev's 28.5 percent holding in Zhujiang Beer Ltd. They will also be prohibited from linking up with two leading Chinese breweries, Huarun Snow Beer Ltd. and Beijing Yanjing Beer Ltd.
The U.S. Department of Justice cleared the deal last week after InBev agreed to sell Labatt USA, which sells the Canadian beer in the U.S. It will hold on to Labatt in Canada. InBev did not say who would buy the American unit.
U.S. antitrust officials had worried that beer prices would increase in upstate New York because - with Budweiser and Labatt Blue - the two companies would supply most of the beer in the region.
InBev has borrowed $45 billion to pay for the deal and secured $9.8 billion in equity bridge financing that it had planned to replace with a share issue in October.
But rocky financial markets forced it to postpone issuing new shares and it says it can keep the bridge financing in place for up to six months after it closes the deal and issue shares early next year.
InBev says the company is well positioned to cope with a slowing global economy because costs for key ingredients such as grain malt for brewing beer and aluminum for beer cans will fall even as sales stall.
InBev is renowned for shaving costs since it was formed in a 2004 merger between Belgium's Interbrew and Brazil-based AmBev.
Beer industry analyst Plato Logic says beer sales will slow significantly to expand just 3 percent next year as economies around the world shrink or stagnate.