UPDATE 1-Storm Barry heads for Mexico Gulf coast oil installations

MEXICO CITY, June 19 (Reuters) - Tropical Storm Barry, the second of the Atlantic Hurricane season, churned toward Mexico on Wednesday, threatening to bring heavy rains to key oil and power installations near the country's Gulf coast.

The Minatitlan oil refinery of state oil monopoly Pemex and the Laguna Verde nuclear power plant, both in Veracruz state, are being monitored closely, said Noemi Zoila, head of the local government's emergency services.

The nearby Coatzacoalcos coastal oil export terminal, one of the most important for Pemex, is also in the path of the storm and was expected to be shut down by 7:00 p.m. local time.

Mexico's two other major oil export hubs, Cayo Arcas and Dos Bocas, were closed earlier on Wednesday due to heavy rain and reduced visibility.

Barry was located about 75 miles (120 km) east-northeast of the port of Veracruz, moving at 10 miles per hour (16 km per hour) as it approached land, the U.S. National Hurricane Center said.

The storm's maximum sustained winds stood at 40 mph (65 kph), the center added.

The biggest impact is expected to be felt in southern and central parts of Veracruz state late on Wednesday night and early Thursday morning, said local emergency services spokesman Manuel Escalera.

Escalera added that the storm could cross Pemex's installations as well as hydroelectric dams. He said the state is prepared to offer temporary shelter to up to 500,000 people.

The first tropical storm of the 2013 Atlantic Hurricane season, Andrea, formed in the Gulf of Mexico on June 5 and moved up towards Florida, Georgia and North Carolina.