It is the second time Shell's Jeroen van der Veer and Gazprom's Aleksei Miller have met in the past two weeks.
At their previous meeting last week, Shell reportedly offered Gazprom a controlling stake in the $22 billion project.
The heads of Japan's Mitsui and Mistubishi companies, Shell's partners in the project, were also in Moscow for the talks.
Russian environmental authorities have threatened the Sakhalin-2 operator with administrative sanctions, withdrawal of key permits, and environmental-damage claims in what analysts see as an attempt to improve Gazprom's bargaining position in the project.
(Reuters, Interfax)