ConocoPhillips is preparing the sale of noncore oil and gas producing acreage in the United States, in the latest sign that oil majors are becoming more accepting of lower oil prices, according to people familiar with the matter. While the world's oil and gas companies have been looking to buy assets on the cheap since oil prices plummeted, epitomized by Royal Dutch Shell Plc's agreement earlier this month to buy BG Group Plc for $70 billion, they have been reluctant to sell assets in case oil prices recover and they can fetch more.