Revenue estimates for the State of Maryland have been increased $5.5 million for fiscal year 1981 and $2 million for fiscal year 1982 by the Maryland Board of Revenue Estimates. The revisions will bring the projected general fund balance to $110,896,000 at the end of fiscal 1981 and to $7,637,000 at the close of fiscal 1982.

In a report to Gov. Harry Hughes, the board, which consists of State Comptroller Louis L. Goldstein, State Treasurer William S. James and State Budget Secretary Thomas W. Schmidt, said the increases were mostly due to one-time, nonrecurring items and that it had actually decreased its estimate of retail sales tax revenue by $11 million for fiscal 1981 and by $10 million for fiscal 1982.

"It was necessary to reduce the sales tax estimate because those revenues have been running below estimates for the past three months," Goldstein said. "Continued high interest rates, inflation and unemployment are factors that still cloud the sales tax picture."

State income tax revenue remains close to the estimate, the board revealed, and interest earned from state investments is exceeding estimates. The board increased its estimate of interest income by $10 million to $63 million in fiscal 1981.

The fiscal 1981 estimate for revenue from the State Lottery was lowered $2 million to $173.6 million, because of uncertainty surrounding the future of the "instant" lottery game.

The board cited three factors that could adveresely affect state revenues in fiscal 1982: legislation to prohibit the operation of all "instant" lotteries; pending budget cuts affecting revenue-producing units of the State Comptroller's Office; and President Reagan's proposal to accelerate the depreciation on business assets, which would reduce Maryland's corporate income tax receipts by $8 million for fiscal 1982.