Brent crude, the international benchmark, fell 27 cents to $64.28 per barrel in London, having dropped $4.47 the previous session. The attack on oil producer Saudi Aramco's processing facility in Abqaiq saw crude surge more than 14% on Monday, about as much as it did when Iraq invaded Kuwait before the 1991 Gulf War.
The attack led to a 5% drop in global output, but Saudi Arabia said it would be restored by the end of the month. Yemeni rebels claimed responsibility, but U.S. officials said they suspected Iran, Saudi Arabia's regional rival. Signs of an escalation in tensions could push the oil price up again, analysts say.
Saudi Arabia said Wednesday it was joining a U.S.-led coalition to secure the Mideast's waterways. The U.S. formed the coalition, which includes Australia, Bahrain and the United Kingdom, after attacks on oil tankers that American officials blame on Iran, as well as Iran's seizure of tankers in the region. Iran denies being behind the tanker explosions.