Standard & Poor's has cut the credit ratings of six government-backed entities and a leading property firm at Dubai.
Earlier, Dubai's finance ministry sold $US10 billion in bonds to the United Arab Emirates, to ease the emirate's liquidity problems.
Dubai is one of seven members of the UAE federation.
S&P said that the worsening world economy could hit sectors vital to the Dubai economy such as trade, tourism and commerce.
The downgrades followed a cut to an in-house sovereign rating S&P has for Dubai, a rating which remains confidential.
The six bodies affected by the cut, by one notch, are: DIFC Investments, port operator DP World, Jebel Ali Free Zone and JAFZ Sukuk Islamic financing package, the Dubai Multi Commodities Center Authority and Dubai Holding Commercial Operations Group.
Despite the cutback, the BBC reports all remain at investment-grade at 'A-' or above.
S&P also cut its long-term corporate credit rating on Dubai property developer Emaar Properties PJSC to 'BBB+' from 'A-'.