Dec 13 (Reuters) -
** Royal Dutch Shell said that five-day strike atits 404,000 barrels per day (bpd) Pernis refinery in theNetherlands has led to lower production rates at certain units
** Parts of the production processes have been disrupted butthe extent of the impact is uncertain, a Shell spokeswoman saidin a statement
** "We monitor the situation closely and are informingcustomers as we see appropriate," she said, declining to commenton which units are affected
** Strike action is likely to continue until the labourunion votes on a new proposal put forward by Shell on Tuesday ina pay dispute, she added
** A spokesman for the FNV union was not immediatelyavailable for comment
** A partial shutdown of the refinery's 65,000 bpd CCR2hydrocracker started on Friday evening, according to a spokesmanfor the FNV union. Capacity at the unit was expected to bereduced by around 20 percent, he said. The lower production wasalso expected to impact other units, including the associatedcrude distillation unit