Icahn raised his TWA stake to 45.5% from 40.6%.

Corporate raider Carl C. Icahn, who is offering $24 per share to acquire all of Trans World Airlines, said he bought the additional shares Tuesday for $38.2 million. The increase could make it harder for Texas Air to win majority approval from TWA shareholders for its competing $23-per-share bid for TWA. However, the record date for shareholders to be eligible to vote on the Texas Air offer is July 25, when Icahn had only 34.4%.