UPDATE 2-Venezuela Chavez nationalizes iron companies

(Adds new quote, Tenaris, production details)

CARACAS, May 21 (Reuters) - President Hugo Chavez on Thursday ordered the nationalization of iron companies that include Japanese capital, part of a drive to build a socialist state in the OPEC nation.

Chavez, who has already nationalized many of Venezuela's largest industries, named iron briquette makers with Japanese investors among the companies to pass into state hands.

"Nationalize the iron briquette sector, there is nothing to discuss," Chavez said to euphoric union members during a televised speech in which he also announced a wage rise for thousands of workers and a cut in management salaries.

Iron companies Comsigua, Orinoco Iron, Matesi are affected by the announcement along with the local unit of transnational Tenaris (TENA.BA)(TS.N)(TENR.MI) steel pipes for the oil industry.

Shareholders in Comsigua include Japan's Kobe Steel (5406.T), Mitsui and Sojitz (2768.T) and much of the region's iron production is sold to Asia, Europe and the United States.

Together the companies produce millions of tonnes of iron annually. Iron briquettes are used in the production of steel.

Several of the companies named on Thursday have long been plagued by labor disputes.

A close ally of Cuba, Chavez has gradually reduced the private sector in Venezuela, taking over major oil, electricity and cement projects in a two-year drive that also includes Venezuela's main steel plant, Sidor.

In recent weeks, he has moved against smaller oil service companies and U.S. food giant Cargill's local operations. (Reporting Frank Jack Daniel; Editing by Peter Cooney and Ben Tan)