<p>Tranz Rail has accused Standard & Poors of lacking objectivity and being inconsistent in the way it has rated the company.</p> <p>The New Zealand rail operator last week dropped S&P from its contractual obligations to rate the company.</p> <p>Upon receiving notice of disengagement, S&P said it intends to downgrade the company to B-, Tranz Rail said.</p> <p>"It remains the company’s view that S&P has been inconsistent in the way it has applied its rating and its current rating is not supported by objective analysis," the operator said.</p> <p>S&P had not taken into account positive restructuring achievements, Tranz Rail said. </p> <br />