March 1 (Reuters) - Wheat export premiums at the U.S. Gulf Coast were mostly steady on Thursday, underpinned by moderate export demand highlighted by Iran's first purchase of U.S. wheat since 2009, traders said.
* The U.S. Agriculture Department confirmed a private sale of 120,000 tonnes of U.S. hard red winter wheat to Iran for shipment by the end of May.
* Some traders said they expected further grain deals from the U.S. and other suppliers to Iran following its crop-cutting drought. The prompt shipment of recent purchases, which totaled more than 2 million tonnes this year, suggested an urgent need for foodstuffs, traders said.
* U.S. soybean export premiums at the Gulf of Mexico were steady to firm on Thursday, supported by steady demand from China amid high prices and shipping woes in South America, traders said.
* Elevated prices for new-crop Brazilian soybeans keeping U.S. soy competitive in the world market into the summer months, a period normally dominated by South American soy. Heavy seasonal shipping congestion keeping nearby Brazilian prices high and availability limited.
* Argentine dock worker strike slowed grain shipments and could disrupt the start of the export season if demonstrations last into the main harvest season.
* Corn export premiums at the U.S. Gulf held steady on Wednesday amid moderate export demand from regular U.S. customers, traders said.
* A large South Korean feedmaker will tender to buy at least four cargoes of corn later this week, a trader said.
To check displays of FOB basis, click on following:
U.S. FOB Gulf corn
U.S. FOB Gulf soybeans
U.S. FOB Gulf SRW wheat
U.S. FOB Gulf HRW wheat
* FOB U.S. Gulf Grain
* U.S. grain export summary
* Brazil soybean export prices
* Brazil corn export prices
* Argentine grain prices
* Russian grain prices (Reporting by Karl Plume in Chicago; Editing by Meredith Mazzilli)