With time and two sweetened offers, Dutch consulting giant ARCADIS NV has prevailed in its two-month quest to acquire U.K.-based Hyder Consulting PLC.

The Dutch firm's chief rival, Tokyo-based engineer Nippon Koei Co. Ltd, said on Sept. 12 that it will not proceed with its planned purchase and has withdrawn a $435-million acquisition offer made in August to counter ARCADIS' first bid.

The announcement follows ARCADIS' move earlier this month to increase its offer by about $12 per share, to $476 million; the price is up more than $65 million from the Dutch firm's original offer in July.

The increased offer follows a move by ARCADIS to acquire enough shares or shareholder commitments to sell shares, to give the Dutch buyer a 28% stake in Hyder that would have been enough to block a rival bid, say UK analysts.

"While Hyder represents an attractive fit with Nippon Koei, and is clearly an excellent company, an acquisition at the current valuation level would present challenges to value enhancement for us," particularly because the UK firm would have remained a standalone unit as part of the deal, said Nippon Koei President Noriaki Hirose, in a statement.

There were no separate statements at ENR press time on Sept. 12 from Hyder or ARCADIS.

Hirose noted with "regret" the impact of the back-and-forth process on Hyder's employees and clients, but added that the Japanese firm "retains its strategic vision to become a top-tier" global consultant, and will continue its hunt for "partners" to accomplish the goal.

Hyder employs about 4,500 staff with sales of around $500 million.

Over half of its business is in transportation infrastructure with buildings and utilities each accounting for about 20%, and environmental work making up the balance. 

But even as it waited out the Hyder saga, ARCADIS moved to acquire Seattle-based global architect and design firm Callison. That deal, whose terms were not disclosed, is set to close in the third quarter, said Callison in an Aug. 25 announcement.

Callison ranks at No. 73 on ENR's list of The Top 500 Design Firms, with $160.9 million in 2013 revenue including $88 million gained from non-US operations.

ARCADIS says the firm's addition will provide a larger position in China and in mixed-use and commercial design. Callison has 1,000 employees.

ARCADIS ranks at No. 10 on ENR's list of the Top 150 Global Design Firms, with $3.3-billion in total 2013 revenue, including $2.9 billion internationally.