A look at the largest brewers as the 2 biggest, AB InBev and SABMiller, consider combining

The world's largest beer brewers have a few things in common: they're very large, very old, and they often have very close relationships with their competitors. That would increase if Budweiser maker Anheuser-Busch InBev buys Miller brewer SABMiller, uniting the two largest beer makers.

Anheuser-Busch InBev NV

Brands: Budweiser, Bud Light, Corona, Beck's.

Latest annual revenue: $47.1 billion.

Size: World's largest brewer. According to Euromonitor, AB InBev has a 21 percent share of the global beer market. It says it makes almost half the beer sold in the U.S.

History: The company traces its lineage to a brewery in Belgium in 1366. AB InBev was created in 2008, when Brazilian-Belgian brewer InBev bought U.S.-based Anheuser Busch. The company later acquired Mexico's Grupo Modelo, although it sold Modelo's U.S. business.

SABMiller PLC

Brands: Miller, Peroni, Milwaukee's Best, Grolsch.

Annual revenue: $26.3 billion.

Size: World's second-largest brewer, with a market share of almost 10 percent.

History: South African Breweries bought Miller Brewing Co. of Milwaukee, Wisconsin, in 2002. SABMiller sells beers including Miller Lite, Coors Light and Blue Moon in the U.S. and Puerto Rico through a joint venture with Molson Coors. A joint venture with China Resource Enterprises sells Snow, a beer that is only sold in China and is the biggest-selling single brand of beer.

Heineken NV

Brands: Heineken, Dos Equis, Tecate, Amstel.

Annual revenue: $21.76 billion.

Size: About 9 percent share of the global beer market.

History: Founded in 1864 in the Netherlands. Teamed with Carlsberg to buy UK-based Scottish & Newcastle in 2008, keeping the company's cider and beer business.

Carlsberg AS

Brands: Carlsberg, Tuborg, Somersby.

Annual revenue: $9.77 billion

Size: A 6 percent global market share

History: Founded in 1826 and combined with Danish competitor Tuborg in 1970. Carlsberg acquired Orkla of Norway in 2004, expanding its business in Russia, Scandinavia and the Baltic countries, and built on those moves in the Scottish & Newcastle deal.

Tsingtao Brewery Co.

Brands: Tsingtao.

Annual revenue: $4.55 billion

Size: A global market share of 4.7 percent

History: Founded in 1903 and started exporting beer in 1954. The Chinese state-owned company says its beer is the number one consumer product exported from China.