Up to 1,200 companies in Mexico stopped production because of problems with the supply of natural gas following a rash of pipeline explosions caused by rebels, an industrial group said on Thursday.

The leftist Popular Revolutionary Army, or EPR, has claimed responsibility for four attacks on state monopoly Pemex's pipelines carrying natural gas, liquefied petroleum gas, crude oil and gasoline over the past week.

There are more than a thousand, nearly 1,200 companies, that have been greatly hurt because of the lack of (gas) supply, industrial group Canacintra's head, Victor Manuel Lopez, told Reuters.

Automakers like Honda Motor Co., Nissan Motor Co. and General Motors Corp. are among the companies hurt by the blasts, he said.

Industrial hubs in central states like Aguascalientes, Guanajuato, Jalisco and Queretaro are the most affected by the gas shortage, Lopez said.

Pemex said on Thursday it had restoring natural gas supply to the central city of Queretaro and hoped to restore supply in Jalisco and the city of Guadalajara by midnight. It expects to have supplies fully restored by the end of the week.

Workers at Petroleos Mexicanos connected a bypass to the Mexico-Guadalajara natural gas duct and began tests, the company said in a statement.

Mexico has deployed soldiers and federal police to protect Pemex's oil wells and pipelines from further attacks.

Mexico's stock exchange has also increased security, a director of the market said on Thursday.

We are beefing up our security and preventive measures, exchange director Pedro Zorilla told reporters. There is no clear picture, information is lacking but the facts are worrying without doubt.

Zorilla did not detail the higher security at the exchange, where trading has been little influenced by rebel attacks. The bourse's key index closed up more than 1 percent on Thursday.

Mexico's top glass maker, Vitro, said on Wednesday it had halted operations at two plants, meaning $800,000 less in earnings before interest and taxes per day.

(Reporting by Rosario Torres Limon, Anahi Rama and Cyntia Barrera Diaz)

Mexico Crude oil Energy