The Metropolitan Atlanta Rapid Transit Authority (MARTA) will hold a series of community forums this month to gather input on its fiscal-year 2011 budget, which takes effect July 1, and discuss a looming deficit.

Last year, the agency used one-time federal stimulus funds to balance the budget. However, sales tax revenue — which accounts for 52 percent of the operating budget — has continued to decline.

MARTA is facing a $120 million budget shortfall and, “without a significant and immediate additional investment in public transit,” will have to reduce its budget by 25 percent to 30 percent, agency officials said in a prepared statement. Addressing the shortfall could mean “significant transit service cuts and employee layoffs,” they said.