Fitch Ratings downgraded bonds of Finland's Nokia Group (NYSE: NOK) citing its declining revenue and earnings, a day after it reported a second-quarter loss.

Fitch lowered its rating on Nokia bonds to double-B minus from double-B plus, with negative outlook, noting the smartphone maker may not be able to resume profitable operations soon.

Nokia Thursday reported selling 4 million new Lumia smartphones, twice as many as expected.

Nokia's American Depositary Receipts fell 11 cents, or 6 percent, to $1.75.