The family of former Libyan intelligence agent Abdel Baset al-Megrahi is joining with relatives of some of the bombing victims to appeal for a new investigation.
The attack killed 270 people, many of them Americans.
The relatives told reporters in Glasgow on Thursday that they are lodging an application with the Scottish Criminal Cases Review Commission, the organization that reviews alleged miscarriages of justice.
Al-Megrahi died two years ago after being released from prison on compassionate grounds. Though he had protested his innocence, he had dropped an appeal in order to be eligible for release.