* Trade tensions threaten economic growth in emerging markets
* But U.S. sanctions targeting Iran oil sector loom over markets (Re-leads with lower prices, adds comment, bullet points)
SINGAPORE, Aug 13 (Reuters) - Oil prices dipped on Tuesday as rising trade tensions dented the outlook for fuel demand growth especially in Asia, although U.S. sanctions against Iran still pointed towards tighter supply.
Front-month Brent crude oil futures were at $72.60 per barrel at 0338 GMT, down by 21 cents, or 0.3 percent from their last close.
U.S. West Texas Intermediate (WTI) crude futures were down 5 cents at $67.58 per barrel.
Signs of slowing economic growth and lower fuel demand increases, especially in Asia's large emerging markets are weighing on the oil markets.
"Demand growth from Asia in general is being called into question. This due to the negative impact of trade wars, a stronger dollar and rising funding costs," Ole Hansen, head of commodity strategy at Denmark's Saxo Bank, said in a note late last week.
Despite the gloomy outlook for trade and the potential slowdown in economic growth, oil markets are expected to remain relatively tight, particularly as U.S. sanctions on Iran have started.
"If markets really go into a funk, I'd expect oil to be part of that. But the complicating factor right now is Iran and the sanctions," said Greg McKenna, chief market strategist at futures brokerage AxiTrader.
Because of the conflicting factors in oil markets, McKenna said "I'm staying out of oil at the moment."
The United States has started implementing new sanctions against Iran, which from November will also target the country's petroleum sector. Iran is the third-largest producer among the members of the Organization of the Petroleum Exporting Countries.
"With U.S. sanctions on Iran back in place ... maintaining global supply might be very challenging," ANZ bank said on Monday, although it added that "the U.S. is doing its bit to increase production, with data showing drilling activity is continuing to rise."
U.S. energy companies last week added the most oil rigs since May, adding 10 rigs to bring the total count to 869, according to the Baker Hughes energy services firm.
That was the highest level of drilling activity since March 2015.
However, keeping with the bearish tone of the market, hedge funds and other money managers reduced their bullish positions in U.S. crude futures and options in the week ending on Aug. 7, data from the U.S. Commodity Futures Trading Commission showed on Friday.
The speculator group cut its combined net-long position in New York and London by 9,117 contract to 397,885 during the week, the lowest since June 19, the data showed.
(Reporting by Henning Gloystein in Singapore; Additional reporting by Gary McWilliams in Houston; Editing by Joseph Radford and Christian Schmollinger)