Royal Dutch Shell Plc workers in the Netherlands later today will start a strike, their first in the country in 26 years, to protest the company's proposal to alter the pension plan.

Workers at the 416,000 barrel-a-day Pernis refinery in Rotterdam and the chemical facility at Moerdijk will begin winding down output at 6 p.m. local time, FNV Bondgenoten union spokesman Marco van Moort said today. The unions are also targeting natural- gas production facilities at Nederlandse Aardolie Maatschappij BV, a Shell venture with Exxon Mobil Corp. starting this Wednesday.