NEW YORK, July 26 (Reuters) - North Dakota and Alaska have added the most jobs, while Nevada, California and Florida have lost the most, in the last five years, according to research released on Monday.

The study of U.S. employment trends found 40 states had fewer jobs in May 2010 than they did five years earlier, according to Portfolio.com, a business news site that published the research of private-sector employment conducted by American City Business Journals.

In first place, North Dakota added 21,300 jobs, and Alaska followed by adding 10,100 jobs from 2005 to 2010, it said. North Dakota saw an increase of 3,200 jobs in the last year alone, it said.

North Dakota and other states that added jobs did not undergo the economic volatility of recent years as much as other states, said G. Scott Thomas, a Portfolio.com demographer.

"There was no real estate boom or bubble and, as a result, they kept plodding along," Thomas said. "Now those numbers look fantastic."

Nevada ranked at the bottom of the list, having lost 113,000 jobs in the last five years, followed by California and Florida, it said.

That marked a dramatic change in fortunes for Nevada and Florida, which finished first and second in jobs in a similar 2005 study, it said.

The change illustrates how little can be divined from such data, Thomas said.

"Five years ago, we said Nevada was No. 1, and now it's dead last," he said. "It does make you leery of economic forecasts."

Together, Nevada, California and Florida have lost 1.69 million jobs since 2005, the study said.

Overall, the United States lost 4.51 million private-sector jobs from mid-2005 to mid-2010, it said. The study used U.S. Bureau of Labor Statistics data from the 50 U.S. states and the District of Columbia.

Other states at the bottom of the list were Michigan, Rhode Island, Georgia, Ohio and Arizona. The declines were a combination of real-estate problems, slowed construction and tourism and a drop in manufacturing, it said.

Source: Reuters