Icahn raised his stake in TWA to 23% from 20.5%.

In a filing with the SEC, Carl C. Icahn said he and a group of companies that he controls now own 7.56 million of Trans World Airlines’ 33 million total common shares outstanding. The holdings include 815,300 shares purchased between last Friday and Monday at prices ranging from $16.875 a share to $17.25, the filing said. Icahn’s disclosure came after the close of New York Stock Exchange trading Tuesday, during which TWA’s stock slipped 12.5 cents a share to $17.125. Icahn first disclosed his 20.5% stake in TWA to the SEC last week. In that filing, he said the group might buy more TWA shares and was considering whether to seek control of the New York-based airline. TWA’s president and chief executive, C. E. Meyer Jr., quickly termed Icahn’s investment “uninvited and undesirable.” Meyer said: “We view Mr. Icahn’s continued purchases of TWA stock . . . as an attempt to intimidate us. TWA will not be intimidated.”