UAL Corp.'s United Airlines said Wednesday it raised its domestic fuel surcharge by $10 to $20 round trip, less than a week after the nation's second-largest carrier increased fares to offset rising fuel expenses.

The move, which went into effect late Tuesday, comes after oil prices topped $114 a barrel for the first time, and will likely put pressure on other airlines to follow suit.

Travelers in some markets who were paying a surcharge of $25 one-way will now see that charge increase to $35, spokeswoman Robin Urbanski said. Fliers in markets where United previously did not apply a surcharge -- mostly where it competes head-to-head with low-cost carriers -- will be charged an additional $5 one-way.

Fare increase: Chicago-based United last week raised fares by $4 to $30 round trip, citing "record-breaking fuel costs." That prompted other major carriers to increase their own ticket prices.