UPDATE 3-Cemex slams Strabag pullout, eyes legal action

* Strabag had agreed to buy Austrian and Hungarian units

* Did not get Austrian antitrust approval by June 30

* Cemex disputes decision, considering court action (Adds analyst comment, debt details, share price)

By Robin Emmott

MONTERREY, Mexico, July 3 (Reuters) - Mexico's Cemex, the world's No. 3 cement company, said on Friday it was considering legal action against Strabag (STRV.VI) after the Austrian builder pulled out of a $435 million asset deal.

Strabag dropped its plan to buy Cemex's (CMXCPO.MX)(CX.N) units for 310 million euros because it did not get Austrian anti-trust officials' approval by a June 30 deadline.

Monterrey-based Cemex, which was counting on the money to help it pay back $4.1 billion in debt this year and help in refinancing talks with creditors, said the move was "invalid."

"Strabag is unwilling to fulfill its commitment as specified by the agreement between our companies," said Cemex's Chief Executive Lorenzo Zambrano in a statement.

"Cemex believes the agreement still to be valid and is considering taking appropriate legal recourse," the company said.

Cemex shares fell 3.59 percent on the news to 11.54 pesos.

Under the deal, announced last July, Strabag would have acquired Cemex's cement production and stone and gravel pits in Austria and Hungary, with total revenue of 257 million euros in 2007, the most recent data available.

Strabag won permission from Hungarian antitrust authorities but Austrian authorities' decision was still pending, allowing Strabag to cancel its planned purchase.

"Unfortunately we could not conclude the antitrust procedures in 11 months of talks," Chief Executive Hans Peter Haselsteiner said in a statement.

But since the deal was agreed, global construction activity has slumped and Strabag has cut its outlook for this year as a severe economic downturn has hit its growth plans in Russia and emerging Europe in particular. [ID:nLS992221]

The collapse of the deal is more bad news for Cemex, which is already suffering a sharp fall in cement sales in its lucrative U.S. and European markets and the difficulty of managing $18 billion in debt amid the global financial crisis.

Cemex, which took on short-term loans to buy Australia's Rinker in 2007, met its creditors in New York and Madrid this week to propose a three-year extension on its $14.5 billion in bank debt that is due in three tranches by 2011.

With its cash flow limited by slumping sales, Cemex was looking to asset sales in Europe and Australia to help show its bankers that the company can pay back its debt.

Cemex agreed last month to sell its Australian operations to one of its main rivals, Switzerland's Holcim (HOLN.VX), albeit it at a fire-sale price of $1.6 billion, about half what it paid in 2007.

Debt talks are likely to continue despite the failure of the Strabag deal.

"We think it by far more important the agreement that Cemex reached with Holcim to sell assets in Australia," Actinver brokerage said in a report.

Debt refinancing could double Cemex's annual interest payments to about $2 billion a year, an amount the company can afford but that would constrain its profitability.

($1=.7133 euros) (Additional reporting by Boris Groendahl in Vienna; Editing by Christian Wiessner)