Corporate donations, including in-kind products and services, increased by 5.5 percent during 2009, despite a 3.6 percent decline in overall U.S. charitable giving, according to a highly regarded study.

The study, conducted by the GivingUSA Foundation and Indiana University's Center on Philanthropy, found that corporate giving rose to an estimated $14.1 billion, up 5.5 percent from 2008, or 5.9 percent when adjusted for inflation.

"This unexpected bounce takes corporate giving to within 1 percent of its pre-recession level," states the report, which owes the increase in part to corporations boosting their in-kind donations, which tend to remain steadier than monetary giving in times of recession.

Overall, the report found that estimated total charitable contributions from American individuals, corporations and foundations fell to $303.75 billion in 2009, down from a revised total of $315.08 billion for 2008. The 2009 drop represents a 3.6 percent decline in current dollars.

"Speculation was swirling for many months that charitable giving had to be down by a great percentage in 2009," said Nancy Raybin, chair of the Giving Institute: Leading Consultants to Non-Profits. "Anecdotally, our experts across the country heard that strong giving in December made all the difference, and the totals for the year bear that assumption out."

The study's results reflect giving by more than 75 million households across the United States, more than 1 million companies, an estimated 120,000 estates and about 77,000 foundations.

For the full study, click here.