The sour economy’s dampening effect on philanthropy may be lessening, according to a survey of 2,300 public charities and 160 private foundations released today.

Thirty-seven percent of the organizations reported decreased contributions in the first nine months of 2010, compared with 51 percent who reported declines in the first three quarters of 2009.

And 36 percent reported increased donations, up from 23 percent in the same period last year.

“These figures may herald the beginning of an economic recovery in the non-profit sector, although only time will tell if the trend will continue,” the report summary stated.

The survey was conducted this fall by GuideStar, together with the National Center for Charitable Statistics, the Association of Fundraising Professionals, the Center on Philanthropy at Indiana University, Blackbaud, and the Foundation Center.

Larger organizations, with annual expenses of $1 million or greater, were more likely to report increased contributions.

Half the organizations report receiving most of their contributions in the last quarter of the year. Of those, 36 percent predict increases over the 2009 quarter, while 43 percent expect to hold steady and 22 percent expect declines.

Nearly half of the responding organizations expect their budgets to increase next year.