One of the lead contractors on Central Maine Power Co.’s transmission line upgrade has filed a lawsuit seeking at least $43 million from the utility for what it says are work changes that cost extra time and money. Hawkeye LLC of Hauppauge, N.Y., charges in the suit filed in federal court in Portland that CMP failed to deliver needed material, including wood and steel poles, on time and in sequence. The complaint says the delays made Hawkeye unable to obtain permits and site access to stay on schedule. A Hawkeye spokesman tells The Portland Press Herald, the company expects to finish its work by year’s end, but refused to address the lawsuit specifically. A utility spokesman said Monday the overall project is progressing on time and remains on budget.