* Q3 EPS ex-items 49 cents vs view 52 cents
* Revenue up 20 pct, but short of Wall Street estimates
* CEO says demand for rigs strong despite economic fears
Oct 19 (Reuters) - Noble Corp , owner of the world's third-largest offshore drilling fleet, on Wednesday reported a 57 percent rise in quarterly profit as some of its most lucrative rigs went back to work in the U.S. Gulf of Mexico.
The profits fell short of expectations, as Noble grapples with greater downtime for its deepwater fleet overall. Average utilization for its semisubmersible rigs, for example, fell to 84 percent in the third quarter from 90 percent a year ago.
Yet current demand was strong in key drilling regions around the world, according to Chief Executive David Williams.
"We are witnessing an intensified effort by a number of customers to secure jackup and floating rigs for drilling operations in 2012 and beyond, supporting higher fleet utilization and improving dayrates, in spite of the unstable global macroeconomic picture," Williams said in a statement.
He said two of its semisubmersibles, the Jim Day and Clyde Boudreaux, were expected to get contracts early next year in the Gulf of Mexico and Brazil, respectively.
Third-quarter net profit rose to $135 million, or 53 cents per share, from $86 million, or 34 cents per share, a year before, the first full quarter of the U.S. moratorium on deepwater drilling following the Deepwater Horizon disaster.
Excluding some tax items, Noble earned 49 cents per share, compared with the 52 cents expected by analysts on average, according to Thomson Reuters I/B/E/S.
Revenue grew 20 percent to $738 million, short of the $744 million analysts had expected.
Analysts are expecting steady improvement in activity in the quarters ahead for Noble. On the shallow-water side, Noble has managed to get all its jackup rigs off Mexico to go back to work for Pemex.
The Switzerland-based company is spending heavily to upgrade its fleet. But like industry leader Transocean Ltd , Noble is pondering sales and even a potential spin-off of old rigs to clear the way for the new models.
Diamond Offshore Drilling Inc , another top-five offshore driller, reports earnings on Thursday, and will hold a conference call that follows Noble's call on Thursday morning.
A slide in oil prices since April has weighed on the entire energy services sector. As of the close of trade on Wednesday, Noble had lost a quarter of its value in the past six months, while Diamond is down 21 percent, number-two player Ensco Plc is down 18 percent and Transocean has lost 31 percent.