SAO PAULO Brazilian state-controlled lender Banco do Brasil SA reported on Monday a 29% leap in first-quarter net profit compared to the year-ago period, boosted by a robust performance of its loan book.

Banco do Brasil's adjusted net income reached 8.55 billion reais ($1.71 billion) during the first three months of this year, while analysts polled by Refinitiv expected 8.69 billion reais.

The lender said the results were positively influenced by the performance of its credit portfolio, "which reflects an adequate mix of risk against return."

Its loan book reached 1.03 trillion reais, growing 16.8% year-on-year and 2.7% from the previous quarter, helped by a greater expansion in agribusiness-related lending.

"This performance is reinforced by growth in service revenues, while administrative expenses remained under control," it added in a statement.During the quarter, Banco do Brasil reported 5.85 billion reais set aside for bad loans, more than doubling the figure reported a year ago, but 10.4% down from the previous three months.

The bank again managed to keep delinquency under control during the last three months of last year, with its 90-day loan default ratio at 2.62%, slightly up from the 2.51% reported the previous quarter. Fee income grew 8.1% to 8.13 billion reais, while its return on equity, which measures profitability, landed at 20.8%, 1.8 percentage points above the previous year.

The company's interest income, a measure of earnings on loans minus deposit cost, rose 38% from a year earlier, to 21.16 billion reais.

($1 = 5.0033 reais)

(Reporting by Peter Frontini; Editing by David Alire Garcia and Anthony Esposito)