Members of the Organization of the Petroleum Exporting Countries reached a "preliminary agreement" following talks in Vienna to cut oil production, but specifics on the amount to be cut have not yet been decided, Russian news agency TASS reported Thursday. The agency also said that according to sources, oil production will be reduced from the October 2018 level. OPEC had ended its meeting Thursday without offering specifics on a volume for production cuts. The group is expected to meet with nonmember oil producers, including Russia, on Friday. January West Texas Intermediate crude settled at $51.59 a barrel, down $1.40, or 2.7%, on Thursday.