The news host has also withdrawn and apologised for a series of allegations she made against ITV colleagues.
Aziz was reported to have made claims of race, sex and age discrimination which were due to be heard at a forthcoming industrial tribunal.
She was suspended from her position as presenter of ITV West news programme West Country Tonight last July after allegations over her expenses.
Her departure after four years at ITV West was announced in a statement this afternoon, which said Aziz ''has decided to leave the company for personal reasons''.
She said: ''I have enjoyed my time with ITV, but over the last few months I realise I made serious and damaging allegations against my Bristol colleagues and ITV managers.
''The allegations were made whilst I was very angry and unwell. I now withdraw all the allegations and wish to continue to develop my career.
''I leave ITV knowing that my time at ITV has been amongst the most fulfilling of my career in television and I have the highest regard for the quality of journalism produced there.''
Aziz, Britain's first Asian national news presenter, joined ITV in 2006 after 10 years at Sky.
A spokesman for ITV said: ''Lisa has made a significant contribution to our team. We have now resolved all of the outstanding issues and we wish Lisa success in the future.''
It is understood that a meeting was called at the ITV West newsroom this morning at which an apology from the presenter was read out.
It is believed the letter explained to colleagues she was withdrawing her allegations and apologised to both ITV and the individual ITV managers about whom she had made claims.
Her letter said she would be making no further comment about the matter.
ITV previously said it had investigated Aziz's claims and they were ''baseless''.
The tribunal claim has been dropped as a result of the allegations being withdrawn.
Article from The Telegraph