The parent of ratings agency Moody's Investors Service said debt capital markets were more volatile in the second quarter than in the first quarter.
Chief Executive Raymond McDaniel said the company still expects to earn $1.75 to $1.85 per share for the full year, but he added: We expect that uneven credit market conditions will persist during the second half.
Debt issuance fell in the second quarter from the first quarter as investors fretted over European sovereign debt.
Moody's reported earnings of $121 million, or 51 cents a share, compared with $109.3 million, or 46 cents a share, a year earlier. Revenue climbed 6 percent to $477.8 million.
Excluding a benefit of 2 cents a share related to legacy tax matters and a restructuring adjustment, the company earned 49 cents a share, beating analysts' average forecast of 44 cents, according to Thomson Reuters I/B/E/S.
Main rival McGraw-Hill Cos , which owns ratings agency Standard & Poor's, reported a higher-second quarter profit last week, but said full-year earnings would likely be at the low end of its previous forecast. McGraw-Hill, which also sells textbooks, said it expected a decline in debt issuance and lower textbook sales.
Both Moody's and Standard & Poor's are also facing higher regulatory costs. Ratings agencies have been roundly criticized for not spotting problems that contributed to the global financial crisis.
Under sweeping financial regulation signed into law by U.S. President Barack Obama earlier this month, ratings agencies can now be sued if they recklessly fail to review information in developing a rating.
Moody's said its expenses increased 9 percent to $287.3 million in the second quarter, in part due to higher spending to meet legal and regulatory requirements.
The company said revenue from its ratings business increased 6 percent from a year earlier to $328.6 million in the second quarter.
Most of this revenue increase came from a pickup in high-yield bank loan origination, the company said, noting this more than offset a drop in investment-grade bond issuance.
Revenue from structured debt ratings fell 2 percent from a year earlier to $73.1 million, Moody's said.
Moody's shares closed down 1 percent at $22.64 on Wednesday.
(Reporting by Elinor Comlay; Editing by John Wallace and Maureen Bavdek)