United Airlines expects to make $700 million from extra fees

United Airlines expects to bring in an additional $700 million in annual revenue from charging for second items such as checked baggage, the carrier said Thursday.

On Monday United doubled its fee for a second checked bag to $50.

Another fee that will bring United more cash is a new program allowing travelers to pay extra to earn double or triple award miles on a flight. That is on track to bring in an extra $1.5 million in revenue in its first month after sales to about 20,000 people, said Kathryn Mikells, the company's chief of investor relations. That program alone should be worth tens of millions of dollars per year, she said.

Mikells, who will be United's chief financial officer after November, spoke at an airlines investor conference in New York.

Airlines have been aggressively "unbundling," or charging for items that used to be free but were not used by all passengers, such as checked baggage and meals.

Skyrocketing fuel prices prompted that trend, but on Thursday there was already one sign that competition may push it back: Air Canada said it would stop charging for a second checked bag. It had not added a fee for the first checked bag.