A top international credit rating firm is further cutting its ratings on six Dubai state-linked companies because it says it cannot assume the government will stand behind their debt.

Moody's Investors Service said it made the cuts Tuesday following statements by government officials since Dubai announced plans to restructure its Dubai World conglomerate late last month.

It had already downgraded the six borrowers once, immediately after the Dubai debt announcement.

The debt rating firm says the latest downgrades come because it believes "no meaningful government support should be assumed for any entity that is not directly part of or formally guaranteed by the government."