According to reports, Singh and Gilani had a brief interaction at a reception organised in connection with the international meet.
Sources said a bilateral meeting between them is expected on the sidelines of the South Asian Association for Regional Cooperation (SAARC) Summit to be held in Bhutan from Apr 26.
Sources also that it was Gilani who walked up to Singh at the reception. They met warmly, with smiles on their faces and holding hands momentarily.
They "shook hands and exchanged pleasantries," External Affairs Ministry spokesman Vishnu Prakash told reporters.
Singh and Gilani held bilateral meetings with leaders of a number of countries but not between them.
This is significant since the Foreign Secretaries of the two countries met in Feb for talks that were aimed at breaking the ice in Indo-Pak relations caused by the Mumbai attacks.
After the Feb 25 talks, India had expressed willingness to have further rounds of Foreign Secretary-level meetings but there has been no response from Pakistan.