The company named Stephen Beynon, who previously headed energy firm British Gas's residential business, as his replacement, and said Beynon will join as managing director of its largest division on May 15.

Aggreko, whose kits power major events and cover electricity shortfalls, has been hit by lower demand for its generators from North American oil and gas customers, who cut spending after commodity prices slumped.

The company, whose plants are used to supplement base-load capacity, has also had to price in a "significant" discount to secure a 200 megawatt contract in Argentina -- its single largest market. This move forced Aggreko to issue a profit warning in March.

"After <18 months in the role and disappointing progress in Power Solutions, the MD is moving on. His replacement... has mostly utility experience - which could be indicative of the new growth environment," Jefferies analyst Will Kirkness said.

Fournier was appointed MD of the power solutions unit in November 2015, after an organisational structure shakeup by Chief Executive Chris Weston, during which he replaced the firm's three divisions with two.

"His (Beynon's) considerable experience in running large service-based businesses and his deep knowledge of the energy sector will prove great assets as Aggreko pursues its programme to return the business to growth," Weston said in a statement.

(Reporting by Tenzin Pema in Bengaluru; Editing by Sunil Nair)