UPDATE 1-Navistar profit beats estimates on higher truck sales

(Corrects last paragraph to say revenue missed estimates)

Sept 6 (Reuters) - Truck and engine maker Navistar International Corp topped Wall Street's quarterly profit estimates on Thursday, as hauliers replaced more trucks and strong freight demand boosted vehicle sales.

Revenue in its trucks business, its biggest, jumped 25.1 percent to $1.92 billion in the third quarter ended July 31.

The Lisle, Illinois-based truck maker raised its fiscal 2018 revenue forecast to between $10.1 billion and $10.4 billion, from between $9.75 billion and $10.25 billion it previously forecast.

Navistar, which posted its first full-year profit in six years in 2017, has changed management, cut costs and redesigned its products to recover from a disastrous bet it made on a costly proprietary smog-reduction system.

The company also raised the low-end of the number of Class 8 trucks it expects to sell in fiscal 2018 to 260,000 units from 250,000, while keeping the high-end at 280,000 units.

Orders for Class 8 trucks - the big rigs that haul freight along America's highways and byways - have been rising every month this year through July.

Net income attributable to the company rose to $170 million, from $37 million a year earlier. Earnings per share from continuing operations rose to $1.71 per share from 37 cents per share. (http://bit.ly/2MPPzjK)

Excluding items, the company earned $1 per share, topping analysts' average estimate of 90 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 17.8 percent to $2.61 billion, but missed expectations of $2.66 billion. (Reporting by Arunima Banerjee in Bengaluru; Editing by Shounak Dasgupta and Sriraj Kalluvila)