Granite (NYSE: GVA) and Layne announced the former's bid on February 14 this year. Layne was trading around US$12.50 a share before the offer was tabled, and hit $16.53 on March 9. It has since drifted back to $14.57.

The company had a market value this week of about US$290 million.

Granite's offer price was at 8.2-times projected 2018 EBITDA and valued the target at $565 million including Layne's debt.

Cetus, which has acquired about 10% of Layne, has said the proposed Granite Construction transaction undervalues Layne. It intends to vote against the acquisition at an upcoming shareholder meeting.

"The company welcomes constructive input from its stockholders with the common goal of maximizing stockholder value," Layne management said this week.

"However, the Layne board of directors believes Cetus' analysis results in inaccurate and misleading conclusions.

"The company recommends that stockholders review the definitive proxy statement to be filed with the Securities and Exchange Commission, which will include additional information addressing Cetus' commentary and which is expected to be filed in the second quarter of 2018."

Layne said it had previously explored a "variety of strategic alternatives focusing on growing its business and developing value for its stockholders".

"In connection with this process, Layne considered its prospects on a standalone basis and evaluated potential strategic transactions that included raising growth capital from new and existing sources of capital and potential acquisition, sale and expansion opportunities relating to one or more divisions of Layne's business," the company said.

"Following the completion of the review process, the board unanimously concluded that the transaction with Granite offered a more favourable opportunity for Layne's stockholders than the alternatives considered."