* Spin-off company to have larger, older fleet
* Part of industry push for sharper focus on deepwater
* Noble shares rise 3 pct after hours
Sept 24 (Reuters) - Offshore drilling contractor Noble Corp unveiled on Tuesday a long-planned spin-off of older rigs into a new company that may make an initial public offering next year, as Noble seeks a premium valuation for its best assets.
Shares of Noble, the No. 4 offshore driller by market valuation, rose 3 percent in after-hours trading to $39.
Noble said the split of 44 drilling rigs and other assets from its "high-specification" rigs would take place by the end of 2014, and that the separation may be preceded by an initial public offering of up to 20 percent of the new company's stock.
"By separating these two businesses, we believe each company will be able to better leverage the overall value of its fleet by focusing on the drivers of its particular business," Noble Chief Executive David Williams said in a statement.
The greater capability of ultra-deepwater rigs, and a widening split in the global offshore oil and gas exploration market between them and older models, have led both Noble and larger rival Transocean Ltd to tighten the focus of their fleets.
The existing Noble Corp will control the remaining 35 rigs, including rigs currently under construction that include three ultra-deepwater drillships and six high-spec "jackup" rigs, which drill in water depths of 300 to 400 feet (91 to 122 meters).
Noble tried to sell off its lower-specification rigs last year, but could not find a buyer. Transocean did, however, manage to sell 38 of its own low-specification rigs for just over $1 billion to Dubai-based private equity-backed firm Shelf Drilling International Holdings Ltd last September.
Bankers will wonder if the Noble deal is a prelude to more industry consolidation, since Pride International's 2009 spin-off of lower-spec vehicle Seahawk cleared the way for Ensco Plc to swallow Pride and become No. 2 fleet owner, and then Hercules Offshore Inc's takeover of Seahawk.
Switzerland-based Noble, now in the process of moving its headquarters to London, said shares of the new company would be distributed to Noble shareholders "in a spin-off that would be tax free" for them. Completion of the deal requires a tax ruling by the U.S. Internal Revenue Services, which Noble expects to receive soon.
Wunderlich Securities, which initiated coverage of Noble shares this month with a "buy" rating and a $51 price target, said the spin-off should be a "positive catalyst."
The new Noble will have a fleet of comparable size to jackup specialist Rowan Cos Inc, though Rowan is only now adding ultra-deepwater rigs of its own.
Diamond Offshore Drilling Inc, which said on Tuesday its CEO would step down early next year, has 38 active rigs and seven more being built. Seadrill has 36 active rigs on a comparable basis, and 25 under construction.
Noble shareholders are expected to vote on the spin-off in the second quarter of 2014, and the filing of a registration for an initial public offering, if it occurs, would be made by the end of 2013 or early next year, Noble said.
CEO Williams, in a letter to Noble employees, said there would be no immediate change to day-to-day operations. "Ultimately, we expect there to be job creation for some shore-based positions around the world to support offshore operations that are contemplated to be largely unchanged," he wrote.