* Italian armchair firm to sell to U.S. office furnisher
* Shares rise 18 pct, more than double on the year
* Ferrari family's exit puts some business at risk -analyst
By Isla Binnie
MILAN, Feb 5 (Reuters) - U.S. office furnisher Haworth agreed to pay 2.96 euros ($4) a share for a majority stake in Poltrona Frau before acquiring the rest of the company in a deal the Italian upmarket armchair maker hopes will increase its access to international markets.
Shares in Poltrona Frau soared over 18 percent on Wednesday after Charme Investments, Ferrari Chairman Luca Cordero di Montezemolo's holding company, and fellow Italian investor Moschini S.r.L., said they would sell their stakes to the family-owned U.S. group.
Haworth will then launch a mandatory takeover offer for the rest of the shares at the same price and delist Poltrona Frau from the Milan stock exchange. No value was given for the deal, which Thomson Reuters data puts at about 240 million euros.
Michigan-based Haworth, which employs 6,000 staff and has 600 dealers worldwide, has revenue of $1.4 billion euros while Poltrona Frau made 247 million euros in 2012.
"We can speed up our growth in North America and in countries like China and India ... thanks to this agreement," Poltrona Frau Chief Executive Dario Rinero told Reuters.
"Together we can make more than $2 billion (in sales), and benefit from each other's logistics and distribution networks."
Poltrona Frau makes over 40 percent of its sales in Italy, where consumer spending remains strained as the economy struggles to emerge from recession, and said in September that sales in the Americas, identified by consultancy Bain & Co as the luxury industry's growth engine, had dropped year-on-year.
Italy's luxury goods sector is seen as a bright spot in the still fragile economy, and firms are attracting interest from foreign buyers, with three bidders in the running for 20 percent stake in fashion house Versace, for example.
Poltrona Frau had seen its shares more than double in a year, before Wednesday's rise.
Haworth's offer values the whole company at about 415 million euros, according to Reuters calculations, about 13 times forecast core earnings for 2013.
FERRARI FAMILY EXITS
The exit of Charme, which owns 51.3 percent, could endanger some of Poltrona Frau's fastest-growing business in the future, said a Milan-based analyst who asked not to be named.
Poltrona Frau makes about 27 percent of sales through its "Luxury in Motion" division, which creates leather seats and interiors for yachts, aircraft and car brands including Ferrari, Maserati and Fiat. Revenue from this segment grew 35 percent year-on-year in the first nine months of 2013.
"Part of Poltrona Frau's business is generated through groups that are close to Charme," the analyst said. "The old shareholder has a good network of connections with Ferrari and Fiat."
Before moving to Ferrari, Montezemolo was chairman of Fiat and used to run Italy's main business lobby Confindustria.
Rinero dismissed the suggestion the company could suffer after Charme, which started building up a stake in Poltrona Frau in 2003, retreats from the scene.
"We have been active in this division for 30 years," Rinero said. "The clients we have secured in recent years came to us because they recognise the quality of our products."
As part of the deal, Haworth has an option to sell back a 4.2 percent stake in Poltrona Frau each to Charme and Moschini.
The transaction is due to be completed by the end of April 2014, subject to approval from antitrust authorities.