The striking writers and heads of the four big Hollywood studios have concluded a "marathon session" of negotiations, which lasted more than ten hours, without a deal, a person familiar with the matter told CNN.

The person, who requested anonymity because they were not publicly authorized to discuss the matter, said that more progress was made during the negotiations Thursday, the second straight day of talks between the two sides, but a deal still has not been inked to end the historic Hollywood work stoppage.

It's unclear when the studios and writers will meet again to continue negotiations.

- This is breaking news and will be updated.