* Ida strengthens after reforming as hurricane

* Expected to enter energy-rich Gulf of Mexico Sunday

* Mexico issues hurricane watch for parts of Yucatan

MEXICO CITY, Nov 8 (Reuters) - Hurricane Ida strengthened in the Caribbean off Mexico's Yucatan Peninsula on Sunday and was expected to move into the southeastern Gulf of Mexico later in the day, the U.S. National Hurricane Center said.

Top sustained winds for Ida, which reached hurricane status again late on Saturday, picked up to 90 mph (145 kph), the Miami-based hurricane center said. It was a Category 1 storm, the lowest rank on the five-step Saffir-Simpson intensity scale.

"Some additional strengthening is expected during the next day or so, but a slow weakening is expected to begin on Monday," the hurricane center said in its 1 a.m. EST (0600 GMT) advisory.

Ida first became a hurricane on Thursday off the Caribbean coast of Nicaragua before weakening over that country. It revived on Saturday.

The center of Ida was 110 miles (177 km) east-southeast of Cozumel, Mexico, and about 120 miles (193 km) south of the western tip of Cuba.

It was moving north-northwest near 12 mph (19 kph) and was forecast to move through the Yucatan Channel and into the Gulf of Mexico later on Sunday, the hurricane center said.

Mexico posted a hurricane watch for the Yucatan Peninsula from the resort of Tulum to Cabo Catoche, north of Cancun.

A tropical storm warning was in effect for Grand Cayman Island and for the western Cuban province of Pinar del Rio, the hurricane center said.

The Mexican government urged people to avoid unnecessary travel in the Yucatan Peninsula and imposed restrictions on coastal shipping.

Mexico's state oil monopoly, Pemex [PEMX.UL], which has extensive operations in the Gulf of Mexico, activated its hurricane contingency program but oil and gas production was unaffected, a company spokesman said.

U.S. energy companies said on Friday they were monitoring the storm's progress but had not yet begun evacuating any production platforms.

The Gulf of Mexico accounts for a quarter of U.S. domestic oil production and 15 percent of natural gas output. The Gulf Coast is also home to 40 percent of the nation's refining capacity.

Ida dumped heavy rain along Nicaragua's Caribbean coast last week, but there were no reports of fatalities. The country's coffee crop was not directly affected by the storm, according to the local coffee council. (Reporting by Robert Campbell; additional reporting by Jose Cortazar in Cancun; Writing by Peter Cooney; Editing by Alison Williams)

AlertNet news is provided by