UPDATE 2-Mexico's Cemex says all creditors support debt deal

* Cemex says all creditors support debt proposal

* Company says agreement still not finalized (Adds background, byline, share price)

By Gabriela Lopez

MONTERREY, Mexico, Aug 10 (Reuters) - Mexico's Cemex, the world's No. 3 cement maker, said on Monday all its creditors have indicated they will support a proposal to refinance $15 billion of debt maturing over the next two years.

In the toughest market in its century-long history, Cemex has been under immense pressure to reach a deal to extend debt it took on to finance its acquisition of Australia's Rinker in 2007.

"Cemex is currently in the documentation phase. Conditions ...related to the agreement are expected to be completed soon," Cemex (CMXCPO.MX) (CX.N) said in a statement.

Cemex had said at the end of July that 90 percent of its creditors backed its plan to refinance the $15 billion debt through 2014.

But fears it would fail to satisfy creditors have weighed on Cemex since last year when the global credit crisis made it harder for even the largest emerging market companies to borrow in dollars.

As the world's biggest economy struggles through its worst recession in decades, Cemex expects cement volumes to fall by up to 30 percent this year in the key U.S. market and prices are also under pressure.

Limping through the global slowdown, Cemex's revenue fell 33 percent in the second quarter to $4.2 billion.

Shares of Cemex slipped 0.64 percent to close at 14.09 pesos before the company announced the progress on its debt negotiations.

Cemex operates in 50 countries and competes globally with Switzerland's Holcim (HOLN.VX) and France's Lafarge (LAFP.PA).

Scrambling to raise cash, Cemex agreed in June to sell its Australian operations to Holcim at a fire-sale price of $1.6 billion, about half what it paid in 2007.

But Cemex's efforts to sell its Austrian assets have faltered after Vienna-listed Strabag (STRV.VI) pulled out of a $435 million asset deal to buy Cemex units.