Marconi PLC G.E.C. 1972 Pension Plan, Stafford, England, will conduct a tri-annual actuarial study beginning in April, said Joe Kelly, spokesman. Watson Wyatt, actuary for the £2.7 billion ($3.9 billion) plan, likely will conduct the study. Changes could occur in the asset allocation as a result of new U.K. accounting standard FRS 17, which will force the company as of 2003 to account for pension assets on the balance sheet. Mr. Kelly would give no further details.