WSP Global Inc. is giving up its effort to buy British consulting firm RPS Group plc.

The Montreal-based company says it will not be revising its offer for the company in the face of a rival offer by Tetra Tech Inc.

WSP had announced a deal in August to buy RPS, which focuses on climate change and energy consulting, for 206 pence per share or about 591.1 million pounds.

However, Tetra Tech topped the offer with a bid of 222 pence per share or about 636 million pounds.

WSP says it "continues to value a disciplined approach to acquisitions to maximize shareholder value."

It says it remains confident in its ability "to capture future opportunities and deliver on its strategic ambitions."