By Jonathan Stempel

NEW YORK, Feb 9 (Reuters) - Identity theft has become more prevalent, with nearly 10 million American victims losing $48 billion in 2008, but the average loss is falling as consumers and businesses detect fraud faster, a new study shows.

The number of victims rose 22 percent to a record 9.9 million in 2008 from 8.1 million a year earlier, with about one in 23 U.S. adults becoming victims, according to the fifth annual study by Javelin Strategy & Research, released Monday.

Total losses increased from about $45 billion, following three straight years of declines. The average loss fell 12 percent to $4,849 from $5,488. One positive trend was that consumers spent less to clear up a fraud -- an average $496, down 31 percent. More than half spent nothing.

The economic recession that began in December 2007 is likely a factor in the increase in theft cases, according to James Van Dyke, the president of Javelin.

"Identity fraud has been dropping until last year, boom, there was a turn-up," he said in an interview. "The only thing we can logically attribute that to is the economy. If people need to make money, and decide to do so illicitly, identity fraud is the logical opportunity."

Improper use of lost or stolen wallets, checkbooks, and credit and debit cards remained the most common means of fraud, constituting 43 percent of all incidents. Roughly one in four victims had personal identification numbers (PIN) compromised on their ATM cards. Online fraud totaled 11 percent of cases.

People who made more than $75,000 were more likely to be fraud victims than those who made less. By age, the fraud rate was highest among people 35 to 44 years old.

Among ethnic groups, Hispanics had the highest rate of being defrauded, followed by African-Americans, Caucasians and Asians. And by geography, fraud risk was highest in California and Illinois, and lowest in New England and the Plains states.