"Blair has been made a scapegoat for British foreign policy regarding Iraq"
Baton Rouge, US
Send us your views
A US official who asked not to be named told the Reuters news agency that Blair was expected to be named as early as Wednesday .
"It is in the final stages of consultation all around," he said.
But a spokesman for Blair's Downing Street office said: "It is by no means a done deal yet."
When asked if Blair was about to be named as the Quartet's envoy, Condoleezza Rice, the US secretary of state, told reporters: "Stay tuned".
"I certainly hope that this role is going to be filled because I think it is very important," Rice said.Final day
Blair is being replaced by Gordon Brown, the finance minister, on Wednesday after 10 years in the position.
Blair will answer questions from MPs in parliament for the final time, before heading to Buckingham Palace to officially tender his resignation to Queen Elizabeth II. Brown will then visit the monarch to be appointed prime minister.
At his final news conference as British leader on Tuesday, Blair said he was ready to help bring about a solution to the Israeli-Palestinian issue.