PRECAMBRIAN SHIELD TAKES 51 MLN DLR WRITEDOWN
  &lt;Precambrian Shield Resources
  Ltd>, earlier reporting a large loss against year-ago profit,
  said the 1986 loss was mainly due to a 51,187,000 dlr writedown
  on its U.S. operations, uneconomic coal and other mineral
  properties.
      Precambrian, which is 89 pct owned by &lt;Mark Resources Inc>,
  said it took the writedown in accordance with new Canadian
  Insititute of Chartered Accountants guidelines for full cost
  method accounting by oil and gas companies.
      Precambrian earlier reported a 1986 loss of 53.4 mln dlrs,
  compared to profit of 4.5 mln dlrs in the prior year.
  

