The Glasgow-based company, which has been restructuring in order to improve efficiency, has forecast a pre-tax profit of between Â£250m and Â£270m.
The figures match those given in the summer when it issued a profits warning.
It also reported a 7% fall in underlying third-quarter revenue.
In a trading statement, Aggreko said sales from its rental solutions division were down 1% on last year.
It added that the ongoing weakness in the oil and gas and mining sectors had been largely offset by continued growth in other sectors, such as petrochemical and refining.
Aggreko also reported an 11% fall in revenue from its power solutions arm, with the "continuing weak economic backdrop in Brazil" having an impact on its business.
In August, Aggreko reorganised the group into two units following a business review.
It also announced plans to add more engineering resources to its Dumbarton manufacturing facility as part of a consolidation process.
Chief executive Chris Weston said Aggreko continued "to demonstrate its resilience against a challenging market backdrop".
He added: "Whilst we are at an early stage in delivering the specific actions identified at our business review in August, I am encouraged with the progress we are making which, regardless of the prevailing market conditions, will strengthen Aggreko and position it well for the future."
By lunchtime on Monday, Aggreko's shares were up by more than 7%.
Temporary power provider Aggreko has said it is sticking to its full-year profit guidance, despite reporting a drop in sales in the third quarter.