By Scott DiSavino
NEW YORK, Sept 13 (Reuters) - Utilities in the U.S. Southeast returned power to almost half of the homes and businesses knocked out by Hurricane Irma, leaving about 4.3 million customers in the dark as of midday Wednesday, in one of the biggest restoration efforts in U.S. history.
The total number of customers still out, representing about 9 million people in Florida, Georgia and the Carolinas, dipped from a peak of more than 7.8 million customers, or over 16 million people, on Monday.
Major utilities in Florida - including NextEra Energy Inc's Florida Power & Light (FPL), Duke Energy Corp and Emera Inc's Tampa Electric - have mobilized tens of thousands of workers to deal with the outages after Irma landed early Sunday and carved a destructive path up Florida, which has a population of about 20.6 million.
FPL, the state's largest utility, said its outages dropped to around 1.9 million customers on Wednesday from a peak of more than 3.6 million on Monday.
In total, FPL said it has now restored power to more than half of its customers affected by the storm. Automated devices restored power to most of the customers who got their power back during the first day, FPL said.
Some Florida utilities, including FPL, warned customers it could take weeks to restore power in the hardest hit areas. FPL said on Tuesday it planned to restore power to eastern Florida by this weekend and to western Florida by Sept. 22.
Irma hit southwestern Florida on Sunday morning as a Category 4 storm, the second most severe on the five-step Saffir-Simpson scale. It had weakened to a tropical depression on Monday.
More than 60,000 workers from across the United States and Canada were involved in the restoration efforts, including those from the affected companies and other utilities, according to the Edison Electric Institute, an industry trade group.
(Reporting by Scott DiSavino; Editing by Phil Berlowitz)