UPDATE 2-Seaway crude oil pipeline purging for reversal - operator

* Flows still scheduled to be reversed June 1 * Lack of pipelines south has depressed WTI prices By Bruce Nichols HOUSTON, Feb 21 (Reuters) - Seaway pipeline has started purging the contents of the crude oil line to prepare for reversal from the Cushing, Oklahoma, storage hub to the U.S. Gulf Coast, a step expected to bring U.S. domestic oil prices more into line with world prices, a spokesman for operator Enterprise Products said Tuesday. "We just started that this weekend.