The brokerage cut its global gross domestic product (GDP) growth forecast for 2011 to 3.1 percent from 3.4 percent, and for 2012, to 3.2 percent from 3.7 percent.
Citigroup said it does not currently expect recessions in the major economies as this slowdown in economic growth is not enough to reverse global profits.
"But we do expect advanced economy growth will remain sluggish to end-2012 at least, with rising unemployment," the brokerage said in a note to clients dated Aug. 24.
For advanced economies, Citigroup cut its growth forecast to 1.4 percent from 1.8 percent for 2011, and to 1.7 percent from 2.2 percent for 2012.
Citigroup also cut its growth forecast for China to 9.0 percent from 9.2 percent for 2011, reflecting weakness in major export markets.
The brokerage does not expect an interest rate hike this year in the world's second largest economy, but sees faster yuan appreciation.