Weaker Ida drenches US Gulf Coast, hits oil supply

* Ida weakens further as it approaches U.S. coast

* U.S. oil, gas production disrupted by Ida

* Storm soaks four states on U.S. Gulf Coast

By Kelli Dugan

MOBILE, Alabama, Nov 10 (Reuters) - Tropical Storm Ida weakened further and was losing speed on Tuesday as it drenched the U.S. Gulf Coast and oil installations, shutting down almost 30 percent of Gulf energy production.

Once a Category 2 hurricane, Ida became less threatening as its top sustained winds fell to near 60 miles an hour (95 kph), the U.S. National Hurricane Center said in a 1 a.m EST (0600 GMT) advisory.

The storm had also slowed down, with its center expected to cross the U.S. Gulf Coast near Mobile, Alabama, later on Tuesday, the hurricane center said.

Forecasters said Ida would continue weakening as it moved over cooler waters before landfall and then lose strength more quickly as it moved inland, turning east over northern Florida.

A U.S. Coast Guard helicopter plucked two workers from a storm-damaged oil rig south of New Orleans. Ida is blamed for 124 flood and mudslide deaths in El Salvador.