The US airline industry has made the second successful attempt in a month to raise fares by $5 to $10 on one-way tickets.

Both moves have been led by Northwest Airlines, which last year sat on the sidelines of similar attempts. Although the latest fare increase, launched on Thursday last week, was matched by most of the largest airlines, JetBlue and South-west, the only profitable carriers in the last quarter, have not followed the fare increases.