Treasury officials have distributed nearly half of the payroll support money earmarked for U.S. airlines and cargo carriers under provisions of the $2 trillion economic rescue package approved by Congress last month.

As of this week, $12.4 billion of the $29 billion in grants has been paid out to 93 carriers to keep front-line workers on the job, treasury officials said. In all, airlines and air cargo carriers are eligible for more than $50 billion in grants and loans.