The pilots union at Trans World Airlines Inc. withdrew its legal petition for an immediate injunction blocking Chairman Carl C. Icahn’s plan to take the airline private. The pilots retained their lawsuit against Icahn’s privatization scheme, however. The pilots’ withdrawal of the petition, which came at a preliminary hearing before New York State Supreme Court Judge Michael J. Dontzin, was in return for a guarantee that Icahn gave at the hearing. The financier, who owns about 77% of TWA’s 30.5 million common shares outstanding, promised that if the pilots’ lawsuit against his plan is decided in their favor, he would reinvest in the airline around $470 million that he originally planned to take out of it. A trial on the pilots’ lawsuit has been scheduled for the first week of December.