INSITUFORM <IGLSF> RAISES STAKE IN UNIT Insituform Group Ltd of Guernsey, Channel Islands, said it has exercised an option to convert a 250,000 stg loan to affiliate Insituform Permaline Ltd to common shares, raising its stake in the unit to 75 pct from 50 pct. The remainder is held by Permaline's management and an investment group. Insituform also said James Colclough has resigned from its board for health reasons and secretary Scott Saltpeter has resigned, effective June Five.