TWA’s purchase of USAir stock is being checked.

The Justice Department is examining Trans World Airlines’ purchases of USAir Group Inc. stock for possible violations of federal law, an assistant attorney general said. Charles F. Rule, acting head of the department’s antitrust division, told a Senate subcommittee that the government is “looking into” whether TWA’s actions complied with requirements of the Hart-Scott-Rodino Act. Last week TWA offered to buy USAir for $1.65 billion cash and subsequently announced it held a 15% stake in the airline.