WASHINGTON — Saying they want to boost competition in the airline industry, Obama administration officials issued new regulations Tuesday aimed at providing passengers with more information to compare the performance of air carriers and the cost of flights.

The Department of Transportation also said it was proposing that airlines be required to refund fees when checked bags are “substantially delayed.” The government already requires airlines to refund fees for bags that are lost, but the proposal would go a step further by including delayed bags. Transportation officials said they haven’t yet defined what constitutes a substantial delay.

Congress directed the department in an aviation bill passed over the summer to require airlines to refund checked bag fees to passengers whose luggage is delayed 12 hours or more for domestic flights or 15 hours or more for overseas flights. However, the department has some flexibility in how it ultimately writes the regulation.

The department also issued several final rules aimed at giving passengers better information when they purchase tickets and for judging the performance of air carriers.

One of the new rules would force airlines to report flight delays for all the planes that fly under their banner. Major carriers haven’t been including flights operated by their regional airline partners in their performance reports to the government. Consumer advocates say that can make major carriers’ records look better than they really are, since the regional flights are more likely to be delayed.

Currently a dozen of the largest airlines report performance data. Under the new rule, Air Wisconsin, Allegiant, Endeavor, Mesa, Envoy, Republic and Shuttle America will also have to report performance data.

Another rule would prohibit online ticketing services from favouring one airline over another in response to consumer searches for flight information.

Airlines will also have to report how many wheelchairs they mishandle. It’s the first time they have had to report that information.

“Airline passengers deserve to have access to clear and complete information about the airlines they choose to fly and to expect fair and reasonable treatment when they fly,” said Transportation Secretary Anthony Foxx.

Airlines for America, a trade association for major carriers, warned that the changes could harm customers by “re-regulating” how airlines sell their products, driving up the cost of air travel.

“It would be difficult to find an industry that is more transparent than the airline industry; customers always know exactly what they are paying for before they buy,” said Nicholas Calio, the association’s president.

The new rules are mostly a “big win” for passengers, said Charlie Leocha, president of Travelers United and a member of the department’s consumer advisory panel. But he noted that the department had delayed final action on some of the rules for more than two years.

Leocha also criticized the department’s plans to start a separate rulemaking process to explore whether airlines should be required to share information with ticket agents on fees for services like checked bags, advance seat assignments and priority boarding. The department has already sought public comments on the matter and consumer advocates had hoped the government was finally ready to take concrete action.

“If DOT is planning on starting from scratch, it will be an enormous retreat from overall airline pricing transparency,” Leocha said.