Shares in Weatherford International plunged nearly 14% yesterday as it struggled to put major accounting errors behind it.
While reporting better-than-expected fourth-quarter revenue, the world’s fourth largest oilfield service company said it expected up to £158million of income tax-related adjustments to previously reported results for 2010 and earlier.
It added that roughly two-thirds of that was attributable to the years 2008 and before.
Yesterday’s announcement followed £316.5million of tax adjustments announced last March for the previous four years.
The accounting troubles have already claimed the job of Weatherford’s top accountant, who was replaced by the chief accounting officer of Transocean.
Switzerland-based Weatherford, whose 50,000-plus global workforce includes a large presence in Aberdeen, said fourth-quarter revenue rose 28% year-on-year to a record £2.35billion.
Pre-tax profits for the final three months of 2011 totalled £160.8million, compared with £75million a year earlier, helping the full-year figure more than treble to £489million.
Revenue over 2011 came in at £8.2billion, up from £6.5billion previously.
Weatherford shares fell more than 13.6% to $15.36 in New York.