* Largest IPO in Germany so far this year
* Braas Monier places shares worth 470 mln euros
* Shares start trading at 23.40 euros, fall as much as 6 pct (Adds comments from CEO, background)
FRANKFURT, June 25 (Reuters) - Shares in Germany's Braas Monier made a weak start to trading in the roofing company's stock market debut on Wednesday, the biggest in Germany so far this year, falling as much as 6 percent.
The stock traded at 22.65 euros at 0925 GMT, below the issue price of 24 euros, which was already near the low end of a 23-28 euro indicative price range.
"There are so many IPOs in Europe these days that investors are getting very choosy," a market participant said.
The company placed shares worth 470 million euros ($639 million), with a supplementary greenshoe option worth a further 71 million euros.
The IPO eclipsed the size of the listings of German car parts maker Stabilus and 3D printer maker SLM Solutions.
"As our business expands we will see our share price rise," Chief Executive Pepyn Dinandt said.
"We expect to reach a gearing (debt level in relation to earnings) of below two by year-end, which would enable us to pay a dividend for 2014," he added.
Following a refinancing deal struck in April and after using 100 million euros of proceeds from the IPO to pay down liabilities, Braas Monier's net debt will stand at 462 million euros.
Analysts expect Braas Monier to post adjusted earnings before interest, tax, depreciation and amortisation of 200 million euros in 2014.
In 2013, Braas Monier posted a net loss of 69 million euros and EBITDA of 84.5 million euros on sales of 1.2 billion euros. The earnings, however, included one-off charges for restructuring of 72 million euros.
The company, founded in 1953, prospered in Germany's reconstruction boom after World War II and later became part of French cement maker Lafarge.
In 2007, Lafarge sold it to French buyout group PAI for 2.4 billion euros, which burdened Braas Monier with so much debt that it was forced into a financial restructuring when building markets suffered from a global economic downturn in 2009.
Creditors such as Apollo, TowerBrook, York and BNP Paribas agreed to swap some of their debt for equity, taking control of Braas Monier and reducing its liabilities.
The flotation gives Braas Monier an enterprise value of 1.35 billion euros, or 6.7 times its expected EBITDA, a discount to the multiple of listed peers, which trade at an average of about 8 times expected earnings.
$1 = 0.7355 Euros Reporting by Arno Schuetze and Alexander Hübner