**One of three men charged with plotting an attack on New York City commuters is expected to change his plea to guilty, US court officials say.**Najibullah Zazi, an Afghan-born Colorado airport bus driver, was charged with planning the bomb attack last September with two other men.
Another two suspects - named as Adis Medunjanin and Zasrein Ahmedzay - were arrested over the plot last month.
They were said to be associates of Mr Zazi, who earlier pleaded not guilty.
At the time of his arrest, investigators said that the imminent threat of an attack had been disrupted but that they would continue to examine a “wide range of leads”.
Prosecutors allege Mr Zazi received al-Qaeda training in Pakistan in 2008.