* UAW membership up 1 pct as U.S. auto market grows
* UAW still relies on investment sales for funding
By Deepa Seetharaman
NEW YORK, April 1 (Reuters) - The United Auto Workers added members for a second straight year in 2011 despite its failure to organize U.S. auto plants operated by foreign automakers, a goal that remains at the heart of the UAW's longterm survival strategy.
UAW membership increased by 4,107, or 1 percent, to 380,719 last year as Detroit's three automakers added jobs amid a 10 percent increase in U.S. auto sales, the UAW's annual financial filing with the U.S. Labor Department shows.
Still, membership is just a quarter of the union's peak size in 1979, when it boasted n early 1.5 million members. In the more than three decades since, the decline in the UAW's membership has taken a toll on its finances.
With assets of more than $1 billion, the UAW is still America's richest union but the bulk of its wealth is tied up in its strike fund and cannot be tapped at will. As a result, the UAW was forced to sell stocks, bonds and other assets to pay for its day-to-day operations during the most recent U.S. economic downturn as the number of dues-paying members fell.
Funding from membership dues rose 3 percent last year, the first increase since 2003, but the UAW continued to rely on investment sales to pay for its activities, the filing shows.
Last year, 16 percent of the UAW's cash receipts came from investment and asset sales, down from 23 percent in 2010. Before 2007, these sales represented 1 percent or less of the UAW's annual cash receipts.
Dues represented 47 percent of the UAW's receipts in 2011.
UAW President Bob King and other union officials have said the key to the UAW's long-term survival is membership growth. The union has organized casino workers and graduate students.
The Center for Automotive Research projects that by 2015,Co, Motor Co and Group LLC will employ 201,000 in the United States, up 17 percent from 2010, but still short of 20 0 8 levels.
Still, the UAW is focused on organizing U.S. factories run by Japanese, Korean and German automakers in the American South, a region that has long been hostile to the UAW.
King aims to convince workers that the UAW has changed and is focused on helping U.S. automakers stay healthy. Concessions made by the UAW to all three major U.S. automakers helped GM andsteer quickly out of bankruptcies in 2009.
Last month, the UAW began soliciting signatures of support from workers atAG's U.S. factory in Chattanooga, Tennessee.
The UAW reported assets of $1.04 billion in 2011 and liabilities of $7.1 billion. Cash receipts and disbursements both fell about 6 percent to roughly $258 million each. (Reporting By Deepa Seetharaman; Editing by Diane Craft)