NEW YORK Oil prices rallied on Friday on news that Iranian oil exports have fallen significantly this month as tightening Western sanctions have caused some buyers to stop or scale back purchases. Iran’s crude exports appear to have fallen in March by around 300,000 barrels per day, or 14 percent, the first sizeable drop in shipments this year, according to estimates from industry consultant Petrologistics and an oil company. After Brent crude futures extended their rise to nearly $4 and U.S. crude also rose sharply, oil prices pared gains following data that showed U.S. new single-family home sales declined in February. The retreat from intraday peaks left both Brent and U.S. crude posting weekly losses. Brent crude rose $1.99 to settle at $125.13 a barrel, having swung from $123.10 to $127.06. Brent posted 68-cent weekly loss, a second straight weekly decline. U.S. crude rose $1.52 to settle at $106.87 a barrel, having traded from $105.16 to $108.25. For the week, it ended 19 cents lower. Brent’s premium to U.S. crude rose to $18.26 based on settlements. Volatility was aided by tepid volumes. Brent trading volume was 4 percent below its 30-day average, with U.S. crude turnover 27 percent below with 1-1/2 hour left in post-settlement trading. “The recent pull backs had not changed the price trend higher and when the (Iran exports) headlines hit the push higher triggered buy stops and the price move also took place on a day with relatively light volume,” said Tim Evans, energy analyst at Citi Futures Perspective in New York. U.S. gasoline and heating oil futures also posted 1 percent gains. The CME Group said on Friday that it plans to list additional months of its New York Harbor heating oil futures contract from May 2013 with an ultra-low-sulfur diesel specification in response to customer requests. Money managers cut their net long U.S. crude futures and options positions, in the week to March 20, the U.S. Commodity Futures Trading Commission, said in a report on Friday. Ahead of the Iranian export news, oil prices had received support from a drop in the dollar. The euro climbed to a three-week high against the dollar. A weaker U.S. currency can lift dollar-denominated crude oil by making it less expensive for consumers using other currencies. The oil complex rally came after crude futures slid the previous session on disappointing Chinese manufacturing data and euro zone PMI figures. Before the price spike on news of slumping Iranian exports, the International Energy Agency’s (IEA) said it did not believe there would be any disruptions to global oil supply as Saudi Arabia and other Gulf producers will bring more oil to the market. Saudi Arabia said Tuesday it was ready to raise its output to 12.5 million barrels per day from current levels just below 10 million bpd. Malaysia’s state oil firm Petronas will halt imports of Iranian crude from April, according to sources in the company. This follows import cuts by major buyer South Korea in the first two months of 2012. In a concession to Asian buyers, the European Union will allow some insurance on Iranian oil shipments before the bloc’s full embargo starts on July 1, member states agreed on Thursday.