Former U.S. officials familiar with the review process said it was unlikely CFIUS would launch its 30-day initial review until after Aug. 10, when Unocal shareholders are expected to vote on the Chevron offer.

• 熟悉审查程序的前官方消息人士称，美国海外投资委员会将启动它的30天的初步调查直到8月10日以后，那一天尤尼科的股东将要投票决定山型公司的收购方案。