* Considers strategic options for Concessions unit
* Says selling shares in IPO one option, would keep majority
* Q2 pretax profit, net income better than expected
* Reiterates earnings expectations for 2009
* Shares rise 5.3 percent, top gainer on the MDAX index
(Adds analyst comment, competitors, shares)
FRANKFURT, Aug 14 (Reuters) - German builder Hochtief said on Friday was considering selling shares in its airports division, seen by analysts as a move that might shore up the company's stock market value.
Hochtief's market capitalisation is made up almost entirely of the value of the majority stake in Australia's Leighton - meaning investors ascribe hardly any value to other parts of the builder.
"Most of Hochtief's value on the stock market consists of its Leighton unit, while other parts -- including the airport business -- are hardly valued at all," said WestLB analyst Ralf Doerper.
"The share sale would give the airport business a value which investors then might also factor in the valuation of Hochtief shares."
Hochtief values the unit, which it calls Hochtief Concessions, at 1.54 billion euros ($2.20 billion).
The Essen-based builder, Germany's largest, was the top gainer on the MDAX index after also reporting earnings for the second quarter that beat market expectations and reiterating its earnings forecasts for 2009.
Leighton is worth $7.7 billion on the stock market, giving Hochtief's 55 percent stake in Leighton a value of $4.2 billion -- almost the entire market capitalisation of Hochtief of $4.3 billion, according to Reuters data.
The builder said it was examining options for the airports division, to increase transparency, but wants to keep a majority and has not taken a decision yet.
"Hochtief is currently checking strategic options for the Hochtief Concessions division ... in this context, an initial public offering is being considered," it said.
The division generated a pretax profit of 110 million euros in 2008, making it Hochief's second-largest earnings generator of the group's six divisions.
It holds stakes in airports in Athens, Hamburg and Sydney and operates roads in Austria and Greece as well as schools in Germany.
Competitors for the division include Ferrovial's British aiport operator BAA, the operator of the airport of Frankfurt, Fraport, and of Vienna, Flughafen Wien.
PROFIT DOWN
Hochtief's pretax profit in the three months through June dropped to 161 million euros compared with 189 million euros in the year-earlier period, but more than the 145 million euro average estimate in a Reuters poll.
Pretax profit -- as well as net income -- for the full year would be on a similar level as in 2009, it reiterated.
Hochtief shares rose 5.6 percent to 46.8 euros at 0914 GMT, while the MDAX index of medium sized companies gained 1.3 percent.
Hochtief trades at 17 times estimated earnings per share for the coming twelve months, compared with an average multiple of 12 of 97 construction and engineering stocks according to StarMine, which weighs analysts' estimates according to their track record.
Hochtief shares have dropped 21 percent in the past twelve months, more than the 17 percent slide of the DJ Stoxx construction and materials index. ($1=.7008 Euro) (Reporting by Peter Dinkloh; Editing by Jon Loades-Carter)