UPDATE 4-Cemex sees first quarter net loss, shares tumble

* Cemex says global slump, weather, hits its earnings

* Company says sells $650 million in convertible bonds

* Shares fall 5 pct in New York and 4 pct in Mexico City (Adds bond sale)

By Robin Emmott

MONTERREY, Mexico, March 24 (Reuters) - Mexico's Cemex, the world's No. 3 cement company, said on Wednesday it sees a likely consolidated net loss in the first quarter of 2010 versus the same period a year ago, hit by the global slump and bad weather in the United States and Europe.

In a filing with the U.S. Securities and Exchange Commission, Cemex said the global economic crisis continued to hurt demand for its cement across its markets. Cemex also blamed severe storms in its key European and U.S. markets for dampening construction in a always difficult winter season.

"It is likely that we will report a consolidated net loss in the first quarter of 2010," the company said. Cemex, which operates in more than 50 countries, is due to report its earnings in the second half of April but has not set a date for the release.

Shares in Cemex fell sharply on Wednesday as investors worried about the near-term outlook for the company.

After the market close, the company said it sold $650 million in convertible subordinated bonds due in 2015 as part of its wider refinancing effort.

Cemex said in a statement it offered the initial purchasers of the notes an over-allotment option of $65 million, subject to certain limitations.

"The notes will be convertible into American Depositary Shares, or ADSs, at an initial conversion rate of 73.5402 ADSs for every $1,000 in notes," the statement said.

Cemex said on Tuesday it was offering $500 million in bonds but stronger demand appeared to allow the company to raise the amount.

Analysts say the bond offer will dilute an already weak share price, while the Mexican peso weakened on Wednesday and sales of newly built U.S. homes fell for a fourth straight month in February.

"Fears about dilution, the (first-quarter) losses, the weakening Mexican peso and U.S. housing data all came together," said Carlos Hermosillo, an analyst at Vector brokerage.

Cemex stock closed down 4.9 percent at $10.46 in New York and 4.06 percent lower at 13.22 pesos in Mexico City.

Cemex is the top cement maker in the United States and reports its global earnings in dollars, so any weakening of the peso hurts its results from Mexico, one of the company's top markets.

Investors are eager to see a recovery in Cemex's sales after it refinanced its debt last year, but fourth-quarter results disappointed [ID:nN26129158].

SLOW RECOVERY

Monterrey-based Cemex executives said in January that the company will start to see an improvement in its sales volumes later this year but that its recovery could be slow.[ID:nN27179904].

"Underlying fundamentals for the construction industry are not yet improving in many markets and severe winter weather conditions in the United States and Europe aggravated the situation," said Vanessa Quiroga, an analyst at Credit Suisse, in a report.

"We believe consensus forecasts for the first quarter have downside risk and we maintain our cautious stance towards the stock," she added.

Cemex, which competes with France's Lafarge SA (LAFP.PA) and Switzerland's Holcim Ltd (HOLN.VX), became swamped by debt after buying Australian rival Rinker in 2007 and default risks hung over the Mexican company for much of 2009.

But it eventually refinanced its $15 billion debt with bankers in August, gaining until February 2014 to pay off the loans.

Cemex, once an emerging market darling famed for snapping up rivals in developed countries, is now seeking to extend some maturities by a few more years. (Additional reporting by Gabriela Lopez; editing by Carol Bishopric)