Mexican materials outfit Cemex made a hostile offer for Australia-based Rinker Group after the Australian Stock Exchange had closed Friday, reports Reuters. The offer values the company at $12.8 billion, a 27 percent premium to the closing price.

Rinker does 80 percent of its business in the U.S. and sees Nevada and Arizona as a big part of its business. You need look no further than the big installation on MGM’s CityCenter site to see the size of its local operations. The buyout would also offer Cemex, which operates in 50 countries, a toehold in Australia and China.

But, reports the Associated Press, it won’t be at the price that was offered Friday. The Rinker Board has yet to make a formal decision but Chairman John Morschel told the ASX, “The preliminary view of the Rinker board is that the proposed offer is opportunistic and materially undervalues the company.”

Update: The Rinker Board has officially rejected the offer but a Cemex executive told a conference call that there wouldn’t be other bidders and that the bid was fair, reports Reuters.

The opportunism is that Rinker is heavily invested in once-booming housing markets like Florida and Arizona and the shares have sunk as fears of the burst bubble have spread. So the profits might soften for a while but the company is having no trouble getting a piece of the commercial action in Las Vegas and probably deserves a bit more. It’s certainly going to ask. Australian analysts are siding with Rinker with the Goldman Sachs saying that Cemex should raise the offer by at least $2-$2.50.