NATWEST, RABO UNIT REPORTS 8.8 PCT PROFIT GROWTH Dutch bank F. Van Lanschot Bankiers N.V., Co-owned by National Westminster PLC <NWBL.L> and RABOBANK B.A. <RABN.A> , said 1986 net profit rose 8.8 pct to 24.1 mln guilders on a 4.8-pct higher balance sheet total of 6.2 billion. Van Lanschot Bankiers is a subsidiary of Van Lanschot Beleggingscompagnie B.V. In which Britain's National Westminster Bank PLC and Dutch cooperative bank RABOBANK Nederland B.A. Each have a 40-pct stake. Commercial Union's Dutch insurance unit <Delta Lloyd Verzekeringsgroep N.V.> has a 5.4-pct stake in Van Lanschot, which lowered risk provisions to 22.5 mln guilders.