(Corrects to seven from six in first paragraph)
* Price tag positive, restructuring challenges ahead * Atos shares up 10 percent to 37.22 euros
(Writes through, adds detail and background)
By Lionel Laurent and Leila Abboud
PARIS, Dec 15 (Reuters) - Atos Origin's bid to create a new European IT powerhouse from the $1 billion purchase of Siemens' SIS sent its shares to a seven-month high on Wednesday, shrugging off concerns of a daunting integration process.
Atos Origin stock rose as high as 38.50 euros, its highest since May, and was up 10 percent at 37.22 euros by 1052 GMT, the top gainer on the broader French SBF120 index, as the market welcomed the deal in which Siemens will take on the bulk of restructuring costs.
French technology group Atos said it expected 2013 revenue of between 9 billion euros ($12.07 billion) and 10 billion from the combined entity, along with an operating margin of 7 to 8 percent.
Atos is paying 850 million euros in a mix of cash and shares, with Siemens taking a 15 percent stake.
Siemens Chief Executive Peter Loescher told a news conference in Paris: "Now we have the scale to really play for the global contracts."
Atos and Siemens said late on Tuesday 1,750 jobs would be cut from SIS in order to boost the unit's profitability, which analysts say is below industry norms. Siemens is taking on 250 million euros of restructuring costs.
"This acquisition has genuine strategic interest ... And the price paid is especially low given that Siemens is carrying virtually all the integration and restructuring costs," CM-CIC analyst Dov Levy said.
"But it carries the usual risks associated with a deal of this size," Levy added.
RESTRUCTURING COSTS
In the year through September, Siemens SIS made a loss of 537 million euros -- partly due to costs relating to job cuts -- on sales which fell 11 percent to 4.12 billion.
Atos Origin Chief Executive Thierry Breton told analysts on a conference call he was "very comfortable" with restructuring cost estimates and forecasts on cost savings.
"SIS has a very strong footprint that we do not have today, mainly in central Europe," Breton said.
UBS analyst Michael Briest said the deal was transformative and would give Atos Origin global reach.
"Today's 850 million-euro price appears attractive. CEO Breton also has a good record on cost-cutting at Atos Origin," he wrote in a note.
Atos Origin has a market value of 2.4 billion euros and competes against the likes of Capgemini, IBM and Accenture.
Atos has long had ambitions to expand in Germany and was courting Siemens' IT unit, then called SBS, as long ago as 2005, a source close to the matter told Reuters at the time -- but the parties failed to reach a deal.
Siemens tried hard in the early 2000s to sell or find a partner for its loss-making IT unit, but in 2006 it said it would keep the business and beef it up with staff from other parts of the group to improve its efficiency and profitability.
The company spent hundreds of millions of euros on restructuring the unit, shedding thousands of staff and cutting about 1.5 billion euros in costs, and sought to integrate SIS into the group by giving it control of Siemens' internal IT.
The unit, which employs more than 30,000, became a separate legal entity carved out of Siemens AG on Oct. 1.
Siemens reorganised its sprawling portfolio that ranges from factory tools to turbines to x-ray machines in 2008 to focus on three core areas -- industry, energy and healthcare -- which it believes will allow it to capitalise on global trends. (Additional reporting by Georgina Prodhan in London; Editing by David Holmes) ($1=.7454 Euro)