Citizen's Bank and Trust Co. of Maryland has reported its net income last year jumped 41 percent to $13.5 million ($8.36 a share) from $9.6 million ($5.96) in 1980.

Total assets of Citizens, based in Riverdale, climbed $53.4 million to $708.3 million at year's end, said Chairman Alfred Smith.

Smith said the addition of seven new branches--four by acquisition of Century National Bank--"has been an important factor in the bank's overall success during the past year."

But he added that growth in earnings was hurt by high interest rates that had to be paid on deposits, which increased by 13 percent during the year.

United Consolidated Industries of Hanover, Md., reported it earned a third-quarter profit of $44,600 (12 cents) compared with a loss of $121,000 in the same period a year earlier.

UCI, a network of auto parts warehouses and distribution centers, had sales of $6 million for the quarter ended Oct. 31, down about $350,000 from the year before.

For the first nine months of its fiscal year, UCI lost $177,000 compared with a loss of $467,000 in the same period a year ago. Sales for the three months ended Oct. 31 dropped almost $50,000 behind last year to $17.68 million.

Record earnings have been reported by Hotel Investors Trust and Hotel Investors Corp. of Chevy Chase.

For the first quarter of 1982, combined profits were $2.05 million (79 cents) compared with $1.4 million (74 cents) for the corresponding period of 1981. Hotel Investors Trust declared a quarterly dividend of 75 cents a share, payable Feb. 1 to owners of record Jan. 18.