Iraq is holding a tender to hire two or more oil supertankers to perform transits through the Strait of Hormuz, the latest evidence that producers in the region are trying to take greater control of their exports through the chokepoint. Iraqi Oil Tankers Co. is seeking the rental for 180 days of at least two very large crude carriers to deliver the nation’s oil through Hormuz, according to a notice on the oil ministry’s website. The tender process closes Thursday.