* Q2 pretax profit rises unexpected 10 pct to 1.62 bln SEK
* Boosted by no writedowns, strong margins in construction
* Says sees sales down just over 10 percent this year
* CEO sees margin pressure, to start shrinking in Nordics
* Shares rise 5 pct, outperforming local bourse
(Adds CEO comments, background, updates share price)
By Anna Ringstrom and Oskar von Bahr
STOCKHOLM, July 23 (Reuters) - Top Nordic construction firm Skanska posted a surprise 10.2 percent rise in its second-quarter pretax profit on Thursday, sending its shares up, but said it still expected revenue to fall this year and next.
It made a profit before tax of 1.62 billion Swedish crowns ($213 million) in the three months, up from 1.47 billion crowns in the same period last year and well ahead of the average forecast of 983 million given in a Reuters poll of analysts.
A Skanska spokesman said the result reflected stronger profit margins than analysts had expected at its construction unit, which accounts for the bulk of its business.
"Practically all our projects have gone well. We haven't needed to make any writedowns on any projects. That, of course, wasn't easy for the rest of the world to know," Skanska spokesman Peter Gimbe said.
Gimbe, however, warned not to read too much into the surprisingly strong second-quarter figures. "We see a tough market ahead and the competition around the projects we are currently fighting for is entirely different."
Chief Executive Officer Johan Karlstrom told Reuters he expected pressure on margins to increase, adding that margins would start shrinking first in the Nordic region.
Skanska generates most of its revenues in the Nordics and the United States, but also has business in the Czech Republic, Britain and Latin America.
Operating profit at the group's main construction unit rose to 1.37 billion crowns from 1.12 billion versus a forecast for 1.18 billion. Order bookings at the unit rose to 37.6 billion crowns from a year-ago 34.2 billion.
In June Skanska had said it would miss its financial targets next year as it reported a fall in orders in the first five months of 2009.
"The report looks strong across the board. The construction (unit) margin is the main point boosting the stock. Capital gains within commercial development were also clearly higher than expected," Danske Bank analyst Peter Trigarszky said.
Shares in Skanska rose 5 percent to 99 crowns at 0821 GMT while the wider market in Stockholm was up 0.3 percent.
TOUGH MARKET AHEAD
"Because of the economic downturn we anticipate revenue declines in a number of markets during 2009, with the Nordic countries and the Czech Republic expected to account for the largest downturn," Skanska said.
"We anticipate that the revenue decline during 2009 as a whole will be just over 10 percent in local currencies. Based on current exchange rates this implies a downturn of about 5 percent in Swedish crowns."
Skanska sees continued revenue declines in 2010, especially in the Nordic countries and the Czech Republic, it added.
Karlstrom said that in the hard-hit Nordic region and Czech Republic, he saw sales shrinking 15 percent in 2009 from 2008.
Quarterly group revenue fell to 35.7 billion crowns from 37.1 billion a year ago, in line with expectations.
Skanska has a long-term goal of achieving an operating margin of 4 percent in the construction business. ($1=7.617 Swedish crowns) (Editing by Greg Mahlich and Simon Jessop)