LONDON (Reuters) - U.S. cement maker Summit Materials (>> Summit Materials Inc) has made a $3.8 billion offer for rival Ash Grove Cement (>> Ash Grove Cement Co), a source familiar with the matter told Reuters, hoping to trump an earlier takeover bid from Irish building materials firm CRH Plc .

Ash Grove said earlier on Friday that it had received a new bid from an unnamed party which valued the business at $3.7-$3.8 billion.

The source said Summit Materials' bid was submitted on Thursday and is currently being considered by Ash Grove's board.

It could be the start of a bidding war with CRH, which last month agreed to buy Ash Grove for a total consideration of $3.5 billion.

(Reporting By Pamela Barbaglia; Editing by Rachel Armstrong)

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