The official APS news agency said it was "decided to extend the agreement by 10 years, with the possibility of increasing the volume of gas exported."
Algeria and Turkey signed a 20-year agreement in 1988 on the sale and purchase of four billion cubic metres of gas annually, and which came into effect in 1994.
Speaking after a meeting in Algiers with visiting Turkish Energy Minister Taner Yildiz, Yousfi told reporters that Algeria's Sonatrach and Turkey's Botas have "already decided on the conditions and terms of the new agreement."
Turkey's rising gas needs are expected to quadruple over the next 10 years.
"We have said we wish to increase our imports to six billion cubic metres a year. Everything will depend on Algeria's export capacity," Yildiz said.