UPDATE 1-Air Berlin says sees stable yields in H2

* Air Berlin says sees stable yields in H2

* Says confirms 2009 outlook, is on track to weather crisis

* Q2 oper profit 17.6 mln eur vs poll avg 16 mln eur

(Adds details, background)

FRANKFURT, Aug 25 (Reuters) - Air Berlin (AB1.DE), Germany's second-biggest airline after Lufthansa (LHAG.DE), said on Tuesday it expected revenue per seat it sells -- the so-called yields -- to remain stable in the second half of the year.

As demand for air travel has fallen, airlines have been trying to lure customers with promotions to keep their planes filled, but Air Berlin has been managing to raise prices over recent months.

The company kept its 2009 outlook, saying it was well on track to weather the global economic crisis, after reporting better-than-expected quarterly operating profit.

Industry body IATA said last week the slide in passenger numbers in business and first class -- the most lucrative sector for airlines -- was showing signs of stabilising. Many airlines had discounted premium tickets to keep seats filled.

Air Berlin said earlier this month its load factor, a measure of capacity utilisation, widened for the first time this year in July as it reduced capacity faster than demand for air travel declined.

In the second half of this year, it expects load factors to decrease slightly due to a further decline in demand, Air Berlin said on Tuesday.

Air Berlin reported late on Monday its second-quarter operating profit rose 33 percent to 17.6 million euros ($25.18 million), topping the 16 million euro average analyst forecast in a Reuters poll. [ID:nLO732568]

Revenues fell by 3.8 percent to 836.2 million euros, in line with estimates.

Air Berlin's stock has fallen by nearly a quarter so far this year and have lost about 70 percent of its value since the company's initial public offering in 2006.

Airlines around the world have been suffering from both rising oil prices and weak air travel demand as consumer and businesses rein in their spending. Industry body IATA has said it sees airlines losing $9 billion this year.

To limit their losses, carriers have cut capacity and grounded airplanes. Air Berlin in July reduced the number of seats on offer by 3.4 percent. (Reporting by Maria Sheahan)