By Jonathan Saul

LONDON, July 20 (Reuters) - Oil transfers between tankers in waters outside the Strait of Hormuz have slowed following a wave of recent attacks on vessels by Iranian forces, according to satellite analysis and sources.

Since the start of the Iran war in late February, ship-to-ship (STS) transfers between tankers have helped enable oil to leave the Gulf despite the threats to commercial vessels sailing through the Strait of Hormuz.