BP PLC (BP, BP.LN) Chief Executive Officer Tony Hayward on Tuesday canceled an appearance at the prestigious World National Oil Companies Congress, where he was scheduled to deliver a speech entitled, "Key roles and responsibilities of international oil companies in an age of economic uncertainty." BP executive Steve Westell filled in for Hayward. Westell told the crowd that Hayward was sorry he couldn't make it and that the CEO's schedule is under "incredible pressure," according to a press report by The Guardian newspaper. Hayward was spotted this past weekend yachting in a race off the Isle of Wight and was reportedly headed for a meeting with Russian president Dmitry Medvedev this week. -Steve Gelsi, 415-439-6400; AskNewswires@dowjones.com (END) Dow Jones Newswires June 22, 2010 08:25 ET (12:25 GMT)