Boeing said on Tuesday it had withdrawn its offer to its largest union and suspended negotiations, while the union charged that the aircraft maker was unwilling to make any improvements to its offer. The International Association of Machinists, with around 33,000 employees, went on strike on September 13, after 95% of its members voted down the company’s previous proposal for a four-year contract. President of Boeing Commercial Airplanes Stephanie Pope said the strike had “deeply affected” the business, customers and communities. Three rounds of bargaining had taken place, she said. “Our team …