The Flyers acquired the rights to Streit last week from the New York Islanders in exchange for a fourth-round pick in the 2014 NHL Draft.
The 35-year-old Streit, who served as the Islanders captain, was scheduled to become an unrestricted free agent on July 5. He finished the 2012-13 regular season with six goals and 27 points in 45 games, then added two goals and five points in six Stanley Cup Playoff games.
"We continue to have talks with Mark's agent," Flyers general manager Paul Holmgren said in a statement. "Although there is nothing to report, we remain confident that we will get something done."
A ninth-round pick of the Montreal Canadiens in the 2004 NHL Draft, Streit has career totals of 65 goals and 288 points in 491 regular-season games. He has 36 career power-play goals.