Obama no closer to replacing ambassador
This is the longest delay by a US president in filling this country's top diplomatic post since 1927.
The American embassy in Dublin was unable to say when an appointment would be made. A spokesman said the White House was "dealing with the matter".
Mr Rooney, who is chairman of the Pittsburgh Steelers, stood down on December 14, 2012. He was the 23rd US ambassador to Ireland.
Sources revealed that a female candidate was "primed" for the job last summer, but the appointment fell through.
There were expectations the job would be filled around St Patrick's Day, with the 'New York Times' reporting that the White House was finalising the selection of a candidate.
Members of the Irish-American community have criticised the delay, with some of them describing it as "a disgrace", a "slap in the face" and "almost scandalous".
They have insisted there must be many suitable candidates given that there are 40 million Irish-Americans.
An appointment is viewed as vital in the context of big issues, including Irish tax policies and their impact on American multinationals and immigration reform.
New York lawyer Brian O'Dwyer claimed the delay showed an "inexplicable indifference to Ireland and the Irish-American community".