Last month, summons issued by the special National Investigation Agency (NIA) court at Panchkula were handed over to the Pakistani authorities, for sending the 13 witnesses to India for the trial.
Pakistan recently conveyed through diplomatic channels that it needed four more months for taking a decision on producing the witnesses before the Indian court, official sources said.
The court, while issuing the summons on March 17, had asked the witnesses to appear before it from July 4.
The NIA counsel would inform the special court about the decision of Pakistani authorities once the court resumes hearing on Tuesday, the sources said. Out of 299 witnesses, court proceedings for 249 have been completed.
Sixty-eight people were charred to death in the blasts in two coaches of the Samjhauta Express in Panipat on February 18, 2007.
The investigators had initially believed activists of the banned SIMI (Students Islamic Movement of India) were behind the blasts, but later concluded that the attack had been planned by a group with right-wing leanings.
The NIA has filed a charge-sheet against several people, including Swami Aseemanand, who walked free in the Ajmer Dargah blast case earlier this year after prosecution witnesses turned hostile.
The NIA had on June 20, 2011, filed the charge-sheet before the special court at Panchkula under various provisions of the Indian Penal Code and Unlawful Activities (Prevention) Act against five people - Naba Kumar Sarkar alias Swami Aseemanand, Sunil Joshi (now dead), Lokesh Sharma, Sandeep Dange and Ramchandra Kalasangra alias Ramji.
The case pertains to an alleged criminal conspiracy which resulted in the blasts in Samjhauta Express.
The NIA, in investigations spreading over almost a year, held that the entire conspiracy was hatched between 2005 and 2007 by Swami Aseemanand, Mr Joshi and their associates at different places including Gujarat and Madhya Pradesh.
The NIA further said Swami Aseemanand was upset with terrorist attacks on temples - Akshardham (Gujarat), Raghunath Mandir (Jammu) and Sankat Mochan Mandir (Varanasi).
The Samjhauta Express, also called Attari Express, is a bi-weekly train that runs on Wednesdays and Sundays - between Delhi and Attari in India and Lahore in Pakistan.