Engineering company Weir Group Plc is close to selling a unit, which supplies pumps and valves to power and oil and gas industries, for more than 300 million pounds (US$390 million), a source with knowledge of the matter told Reuters.

The 148-year-old company said in April 2018 that it would start a process to sell the flow-control division, which contributes about 15% to its total revenue.

The source said U.S.-based private equity firm First Reserve Management was among a number of buyers eyeing the unit.

"The process is ongoing and there are still a number of interested parties that are looking at the asset," the source said.

The proposed sale comes after oilfield services companies were hit by a slowdown in demand last year as regional oil prices fell due to transportation bottlenecks faced by producers.

Weir, which agreed to buy ESCO Corp. for $1 billion last year to bolster its mining business, declined to comment. First Reserve did not immediately respond to a request for comment.

Sky News first reported the development in the sale process on Jan. 31. (US$1 = 0.7634 pounds)