“Global retail sales are expected to slow this year as China and the rest of the BRICs [Brazil, Russia, India, and China] face tightening monetary policy and weaker demand abroad,” Rob Wile of Business Insider writes.

Well, that's the takeaway from Deloitte's annual ranking of the top 250 retail chains by sales at least.

While figures in 2011 saw some decent gains — U.S. sales grew 7.7  percent — Deloitte sees the world economy decelerating in 2012, according to Wile.

"Retailers targeting upscale consumers could see a more favorable environment," Wile writes, "But the average consumer remains on uncertain financial footing and will seek out lower costs, the report states."

The most successful retailers are a mixture of superstores, grocers, drug stores and wholesale providers.  The leaders are U.S. firms, but Germany makes a fine showing.

Here are the 15 top retailers as compiled by Business Insider:

[gallery link="file" order="DESC" columns="2"]

See the Top Three Retailers at Business Insider.