Vujanovic put off the session, scheduled for Tuesday, after meeting the European Union envoy for the referendum, Miroslav Lajcak, in Podgorica on Monday.
The Slovak diplomat told Vujanovic that progress had been made in talks between the government and the opposition on referendum rules.
Lajcak said that agreement had been reached on two of the five disputed issues and that two issues were near settlement. He therefore asked the Montenegrin president to postpone the session.