ATLANTA - Georgia tax collections dropped by about 16 percent in September over the same month last year, continuing a trend set in the first two months of the fiscal year, Gov. Sonny Perdue announced Thursday.

Net revenue collections for September were about $1.3 billion, compared to about $1.6 billion in September 2008. Three months into fiscal year 2010, revenues are down about 14 percent compared to the first three months of last fiscal year.

"There's still some weakness in the economy, which results in lower tax collections, both in sales tax and income tax, and that's really affecting us," Perdue spokesman Bert Brantley said.

Brantley pointed out that September 2008 was "an up month" for revenues, making the year-to-year comparison seem worse. He also noted that the recession hadn't really started yet by September last year.

While some economic indicators have shown signs of improvement lately, revenue numbers often lag behind as it takes time for people to regain confidence and start spending again, Brantley said.

The 2010 fiscal year, which started July 1, has been off to a rough start, with revenues dropping about 10 percent in July.

and 16 percent August. Last month Perdue's office attributed a big part of the drop in the first two months to budget cuts at the state Department of Revenue that caused about 270,000 income tax refund checks to go out in July and August.

But Brantley acknowledged that September's revenue drop, which was as steep as the month before, can't be explained away by lingering refund checks from the last fiscal year.

"There's not as clear of a reason why" for the drop in September, he said.

Corporate income tax receipts, which grew about 10 percent in July over the previous year and dropped just 1 percent in August, were down about 13 percent in September compared to last September.

"It's not heading as quickly in the right direction as we all had hoped," Brantley said. "It's certainly concerning, so the governor and the legislators continue to look at the numbers and the trends. Discussions about the budget never stop."

Brantley said there are no immediate plans to tweak the budget but the governor's office is looking closely to see if more trims are possible.

Perdue met with economic advisers on Monday to discuss the situation, Brantley said.

"There are some differing opinions, but most agree we're going to have a little bit of a rough patch," he said. "But maybe early next year we'll see an improvement."