* Making legal preparations to spin off unit "Verallia"
* 2011 seen as good time for investor appetite
* Initial float of minority stake could be followed by more (Writes through, adds detail)
By Gilles Guillaume
PARIS, Oct 13 (Reuters) - France's Saint-Gobain, the world's largest building materials group, is readying a stock-market listing for its packaging unit as it narrows its focus on construction and residential markets.
The initial public offering would take place in the second quarter of 2011 at the earliest under the name "Verallia", a spokeswoman said on Wednesday.
The packaging unit, which makes bottles and jars for food and drink products, has long been seen as out of step with Saint-Gobain's overall focus on residential and construction goods, the company's chief executive said in a statement.
But previous attempts to sell or spin off the unit were scuppered by the financial crisis.
"The general business environment in 2011 is more likely to ensure that the packaging sector ... will be valued at a price that reflects its true worth," Pierre-Andre de Chalendar said.
Saint-Gobain is now making the legal preparations necessary for an IPO, including meetings with employee representatives, the group said.
It is eyeing an initial listing of less than 50 percent of the packaging unit -- which made 3.4 billion euros ($4.7 billion) in sales last year -- by the second quarter of 2011 at the earliest, a Saint-Gobain spokeswoman said.
Subsequent listings of more of the unit's capital are not being ruled out, the spokeswoman said. (Writing by Lionel Laurent; Editing by David Holmes) ($1=.7173 Euro)