If you plan to fly during the holiday season, the chance of losing your luggage increases sharply.

The rate of mishandled luggage in December was as much as 35 percent higher than the annual averages for 2008 through 2010, according to a study by NerdWallet, a personal finance analysis website. In January, the lost or damaged rate was as much as 43 percent higher than the annual averages for 2008-11.

For example, in December 2010, airlines reported an average rate of 4.7 mishandled bags per 1,000 passengers, compared with the average for the year of 3.47 lost or damaged bags, according to NerdWallet Inc. The trend did not hold true in December 2011, when the rate dropped to 3.25 reports, compared with the annual average of 3.33 reports, according to NerdWallet.

Alicia Jao, NerdWallet vice president of travel media, suggested a simple reason: Around the holidays, travelers carry more luggage with them, increasing the likelihood of lost bags.

“During the holidays, people usually check more luggage than when they travel, say, in the summer,” Jao said.

The study also found that the lost luggage rates are higher among regional airlines. The worst offender, according to the study, is American Eagle, the regional carrier of American Airlines. The airline had 9.19 reports of mishandled bags per 1,000 passengers in January 2011 _ more than double the average rate for all other airlines that year, according to the study.

In a statement, AMR, the parent company of American Eagle, said the airline “continues to make great progress in its baggage performance, with a 28 percent improvement for the first nine months of 2012 compared to 2011.”

(c)2012 Los Angeles Times. Distributed by MCT Information Services.