The revenues of the world's 250 largest retailers grew by 5% to reach US$4trn during the fiscal year ended June 2012, despite the global economic downturn, research has found.

Revenues rose significantly for companies based in Africa, the Middle East, Latin America and Asia Pacific, according to the 2013 Global Powers of Retailing report from Deloitte and Stores Media.

The report found that emerging markets counted for almost half (24) of the fastest growing 50 companies over the 2006-2011 period. Chinese and Russian retailers were well represented among the fastest growing 50, as well as retailers from Africa/Middle East and Latin America.

"The growth in large emerging markets such as China is projected to add at least 70m new consumers to the global middle class per year, which is an additional 500m new middle-class consumers by 2020," said Vicky Eng, global retail lead, Deloitte US.

"This new wave of consumption represents a huge opportunity for consumer businesses.

"A significant investment by a company is required to successfully expand and operate in emerging markets, including gaining a deep understanding of local consumers' tastes and preferences, forging a strong cultural fit with local partners, and attracting and retaining local talent."

Retail revenue for the fastest-growing 50 retailers rose 22% on a compound annual basis between 2006-2011, more than four times faster than the top 250 as a whole.

However, fashion retail did not fare as well, with revenue growth slowing to 5% in 2011 from 7% in 2010.

The report said fashion retailers were the most global of the product groups, with almost 80% operating outside their home countries, operating an average of 21.3 countries.