Feb 8 - Finnish clothing and textiles group Marimekko said 2011 profit would be hit by expansion costs and rising cotton prices, sending its shares down 7.5 percent to reverse gains made in the past fortnight.

Marimekko said on Tuesday its 2011 operating profit would likely fall 40-60 percent from the 8.2 million euros ($11 million) it reported for 2010 and compared with the 8-9 million forecast in a Reuters poll.

Marimekko, known for bright prints and simple lines, said net sales would grow 5-10 percent this year, in line with forecasts.

"The share is obviously down on the weak guidance for this year, as consensus was for pretty much flat profits," Nordea analyst Rauli Juva said.

While Marimekko's fixed costs, especially in the United States, will rise, Juva said the more important reason for the weak guidance lay in rising costs and lower promotion sales in Finland.

"That actually has a bigger impact and they cannot fully off-set the generally higher cost inflation with price increases," he said.

Cotton prices CTc1, which rose 90 percent in 2010, are up another 30 percent this year.

Marimekko raise its dividend 22 percent to 0.55 euro.

(Editing by Dan Lalor)