CARACAS, Venezuela?One of the world’s largest oil refineries virtually shut down, and industries and businesses closed Tuesday during a general strike that Venezuelan President Hugo Chavez tried to keep off radio and TV.

Large industry and commerce closed after the 1 million-member Venezuelan Workers Confederation and Fedecamaras, Venezuela’s largest business federation, called a 24-hour nationwide strike supporting an ongoing work slowdown at the government oil monopoly Petroleos de Venezuela, or PDVSA.

PDVSA workers are protesting a company board appointed Feb. 25 by Chavez, saying the board is unqualified and will tighten Chavez’s control, hindering the corporation’s autonomy.

The slowdown has oil markets on alert following Iraq’s decision to stop oil exports for 30 days to demand that Israeli forces abandon Palestinian territories.