* Estimates 4th-qtr revenue of $510-$520 mln vs est. $556 mln
* Expects to post fourth-quarter profit
* Shares down 4 pct
Feb 11 (Reuters) - Canadian Solar Inc's fourth-quarter revenue estimate missed analysts' estimates as weak panel prices more than offset a rise in demand, sending its shares down 4 percent.
The company, most of whose manufacturing operations are in China, estimated that it shipped between 605 megawatt (MW) and 620 MW of solar panels in the quarter, higher than its target of 480-500 MW.
Still, its fourth-quarter revenue estimate of $510 million-$520 million came in below the average analyst estimate of $556 million, according to Thomson Reuters I/B/E/S.
Solar companies are seeing increased demand for panels and other products, primarily in China and Japan, but prices remain depressed as excess supplies continue to flood the market.
To cut its dependence on the hyper-competitive business of selling panels, Canadian Solar has made a big push into building solar power plants, a high-margin business.
The Guelph, Ontario-based company said on Tuesday it expects to have turned in a profit for 2013, its first annual profit since 2010.
The company, however, warned that its profitability could be hurt if it received an unfavorable ruling in a case over a contract dispute with LDK Solar Co Ltd.
The dispute stems from a wafer supply contract the companies entered into in October 2007 and June 2008, and subsequently terminated.
Canadian Solar also estimated it would post a profit in the fourth quarter ended Dec. 31, its second straight quarterly profit after nine quarters of losses.
The company estimated quarterly gross margins of 16-18 percent. That is higher than its prior forecast of 13-15 percent, which did not include the sale of a solar project in Ontario, Canada.
Raymond James analyst Pavel Molchanov said the gross margin estimate was below the 20.4 percent Canadian Solar reported in the third quarter.
"So it's not really an improvement," Molchanov said.
Canadian Solar also said it was offering 2.6 million common shares and $100 million in convertible senior notes due 2019.
Solar panel makers are returning to capital markets for the first time in more than two years in an attempt to raise funds to pay off billions of dollars of debt.
Canadian Solar shares were down 4 percent at $37.56 in morning trading on the Nasdaq.