DUBLIN (Reuters) - A majority of Ash Grove Cement's (>> Ash Grove Cement Co) shareholders approved the sale of the U.S. cement maker to Ireland's CRH (>> CRH PLC) on Friday after a rival bid from Summit Materials (>> Summit Materials Inc) failed to materialise.

Summit, a U.S. construction firm set up in 2009 by former CRH executives, attempted to outbid their former colleagues earlier this month with a preliminary bid valued at $3.7 (2.80 billion pounds) -$3.8 billion, a source familiar with the matter told Reuters.

Kansas-based Ash Grove, whose board had already unanimously approved CRH's $3.5 billion bid, did not name the rival suitor when it extended the period during which it was able to look for other potential buyers to Oct. 20.

However it named Summit on Friday, saying that it provided confidential information to the Denver building materials group following its unsolicited offer but that Summit did not submit a definitive proposal by the 2100 GMT deadline.

That automatically trigged the approval of 63.4 percent of shareholders who had delivered written consents approving the transaction when the CRH deal was announced, Ash Grove said in a statement.

The deal, which is expected to close in late 2017 or early 2018, pending regulatory approval, will further strengthen CRH's grip in North America where it is the biggest maker of concrete products and second largest supplier of aggregate materials for construction.

CRH, the world's third-largest building materials supplier, is adding the fifth largest cement manufacturer in the United States in family-owned Ash Grove which has extensive readymixed concrete, aggregates and logistics assets across the U.S. Midwest.

(Reporting by Padraic Halpin)

Stocks treated in this article : Ash Grove Cement Co, CRH PLC, Summit Materials Inc