AUGUSTA — Maine started the new budget year with revenues in July exceeding estimates by $14.5 million, but sales tax receipts are lagging, worrying lawmakers and budget officials.

“The sales tax is only running 1.7 percent over last year,” Finance Commissioner Sawin Millett said. “It was projected to be 3.7 percent, and that has to be a concern as we look at what is happening in the economy.”

He said the economic forecasting commission will have to review the sales tax assumptions when they meet this fall to see if the growth rate needs to be modified. He said the various categories of the sales tax are mixed, with lodging nearly 15 percent above a year ago but building supplies 10.2 percent below a year ago.

“We are seeing a slowdown on the retail side from what we were seeing earlier this year in the winter and spring,” Millett said. He said Maine consumers have always been affected by energy prices and that appears to be the case with the increases in gasoline prices this summer.

“Increased prices for oil — gasoline in the summer, heating oil in the winter — has a very quick and immediate impact,” Sen. Richard Rosen, R-Bucksport, co-chairman of the Legislature’s Appropriations Committee, said. “People have less money to spend, and that is reflected in the sales tax.”

He said retail sales are only slightly ahead of last year, and if energy prices continue to increase he is concerned that will reduce the ability of consumers to buy everything from back-to-school clothes to big ticket items such as washing machines.

“The period we are in right now, when people are buying back-to-school clothes and supplies, will tell us a lot about what is happening with consumers,” Rosen said.

August sales tax receipts are reported in September, so it will be October before actual sales figures are available.

“I will be looking very carefully at those reports,” Rep. Peggy Rotundo, D-Lewiston, the lead Democrat on the committee, said. “The sales tax is a key indicator of how Maine families are doing, and if it continues to not meet projections, we need to be concerned.”

While consumers may be reluctant to spend, they may have more cash available to spend. The individual income tax made up most of the increased revenues in July, up $12.1 million with that revenue coming from better than expected withholding payments by employers and higher than projected estimated payments by the self-employed.

“Withholding increased by 7.7 percent in the first month of the fiscal year,” Millett said, “in stark contrast to the 1.3 percent growth experienced for the first half of calendar year 2012.”

He said the withholding numbers are in line with some of the other reports he has heard about slow growth by businesses. He said it appears the economy is continuing to “bump along” with some growth.

“That is what I continue to hear anecdotally,” Rosen said. “There is some growth, but we have not seen the sort of increased employment that everyone wants to see.”

Rotundo said she hopes the additional income tax revenue is an indication that the economy is improving, but she said the economy will not be in a position to really grow until more Mainers are working.

“We are still seeing little growth in jobs and that concerns me,” she said.

Millett said the corporate income tax continues to do better than projected. In July, it was $1.1 million above estimates, which is 12.8 percent above projections made last spring.

“The lottery is another line that was above estimates,” Millett said. “We had some pretty big jackpots, and that always generates additional revenue.”

The lottery brought in a half-million dollars more than was projected, 12.4 percent better than the estimates.

He said two other revenue sources were way above estimates due to timing issues or one-time payments. The estate tax was 47 percent above projections, and the insurance company tax was 213 percent over estimates.