The Mother and Baby Homes Commission of Investigation is to seek an extension of one year before publishing its final report.
The Castle in Newtoncunningham and Stranorlar county home are among properties that are included in the investigation.
The commission was set up following revelations in 2014 by local historian Catherine Corless about the deaths of almost 800 children at the Tuam mother-and-baby home in Co Galway.
The commission, set up in 2015, was originally due to publish its final report last February but it was granted a one-year extension by the Government.
According to the Irish Times, the request has gone to the Government and is expected to be discussed by the Cabinet next week.
It is believed the request is a result of the workload involved in investigating such institutions over the period from 1922 to 1998.Tags: