Oil prices slipped yesterday on expectations for a build-up in US crude inventories, but Russian government comments on prospects for stepping up cooperation with members of the Organization of Petroleum Exporting Countries (OPEC) to coordinate output cuts braked steeper declines. US WTI crude futures were at $63.36 a barrel, down 15 cents, or 0.24 per cent, from their previous settlement while Brent crude futures dipped to $67.94 per barrel, down 18 cents, or 0.26 per cent, after it rose 0.7 per cent on Tuesday. US crude inventories likely saw a build for the second straight week, while refined product stockpiles were forecast to have declined last week, an expanded Reuters poll showed on Tuesday. Industry group the American Petroleum Institute, however, said on Tuesday US crude stocks have unexpectedly fallen last week as refineries boosted output. “With total combined stocks of crude oil and refined products coming in around unchanged on the week, I would call it a neutral data point,” said Dominic Chirichella, senior partner at the Energy Management Institute in New York. “The EIA data has not (always) been in sync with the API data so we could see a different set of data points Wednesday morning,” Chirichella said.