"Sad to hear of the passing of Sayed Mohammed Hussein Fadlallah, one of Hezbollah's giants I respect a lot," said Nasr, who joined CNN in 1990.
She followed that up with a blog post on CNN.com expressing "deep regret" for her 'tweet" about the man considered the spiritual guide of Hezbollah and who figured on a US “terrorist" list.
"This does not mean I respected him for what else he did or said," she said.
Parisa Khosravi, senior vice-president for CNN International News gathering, said that she had spoken with Nasr and “we have decided that she will be leaving the company.
Nasr had covered virtually every major West Asian story for CNN during the past 20 years and anchored CNN World Report and CNN International's World News from 1993 to 2003.
“However, at this point, we believe that her credibility in her position as senior editor for Middle Eastern affairs has been compromised going forward," said Khosravi.
“We thank Octavia for all of her hard work and we certainly wish her all the best," said the CNN official.