Oil prices this week plunged to their lowest level since February 2004, in spite of Opec’s latest effort to steady the market with an agreement to implement the largest supply cut in the cartel’s history, which was announced on Wednesday.

The benchmark US crude price sank below the $33-a-barrel level on Friday. Nymex January West Texas Intermediate dropped to $32.40, a near five-year low, before recovering to settle $2.35 lower at $33.87, down 26.8 per cent this week.