Canon said it now expects to book a net profit of 250 billion yen ($3.2 billion) in 2012, down from the 290 billion yen it had forecast in April.
The maker of PowerShot digital cameras and office equipment also cut its operating profit estimate to 390 billion yen from 450 billion yen while lowering its sales outlook to 3.69 trillion yen from 3.90 trillion yen.
"The global economy is expected to continue (to show) low growth... as the European debt crisis has caused uncertainty," Canon said in a statement.
The revised earnings estimates were largely due to weakness in export markets and currency fluctuations, said Canon, whose overseas revenue accounts for about 80 percent of its sales.
The yen has tipped multi-year highs against the euro and dollar with the strong Japanese currency making exporters' products pricier overseas while shrinking the value of their foreign-earned income.
For the three months to June, Canon said its net profit fell 4.0 percent on-year to 51.7 billion yen while revenue grew 7.5 percent to 899.2 billion yen.