UPDATE 2-Ad company Interpublic misses profit estimates, shares slide

(Adds shares, details and analyst comment)

July 25 (Reuters) - U.S. advertising company Interpublic Group on Tuesday reported lower-than-expected quarterly profit and revenue, hurt by tepid client spending.

Shares of Interpublic, one of the "Big Four" advertising companies of the world, fell nearly 9 percent to $23.30 in premarket trading on Tuesday.

"Client spending in the quarter reflected increased caution, but we don't see evidence of a broad-based economic downturn." Chief Executive Michael Roth said in a statement.

The company said it now expects 2017 organic revenue growth at the low end of its 3 percent to 4 percent forecast range.

Interpublic, which has faced stiff competition from other top ad agencies and consulting firms, has tried to bolster its U.S. business by shaking up management at some of its biggest ad agencies.

However, revenue from the United States, which contributes the bulk of Interpublic's total revenue, fell slightly to $1.16 billion in the second quarter ended June 30.

International sales declined 3.3 percent to $724.4 million in the quarter.

"(The results) were surprisingly weak," Pivotal Research Group analyst Brian Wieser said.

Interpublic's results also contrasted upbeat earnings reports from rival "Big Four" companies, Omnicom Group Inc and France's Publicis.

Omnicom benefited from higher spending by businesses in Europe and the United Kingdom, while Publicis gained from recently-won accounts in North America.

Interpublic, whose clients include Google, Microsoft and Coca-Cola, said net revenue slipped 1.7 percent to $1.88 billion, missing analysts' average estimate of $1.95 billion, according to Thomson Reuters I/B/E/S.

Net income available to IPG fell to $94.7 million, or 24 cents per share in the quarter, from $156.9 million, or 38 cents per share, a year earlier.

Excluding one-time items, Interpublic earned 27 cents per share, missing analysts' estimates of 34 cents. (Reporting by Aishwarya Venugopal in Bengaluru; Editing by Sai Sachin Ravikumar)