Despite U.S. airlines' widely publicized efforts to improve service, government figures released yesterday show that late flights, baggage problems and customer complaints all have increased in recent months.

Nearly one in every four flights arrived at least 15 minutes late during November -- up from one in five the previous month -- and passengers filed more lost-baggage claims, the Department of Transportation said. Some 7.88 baggage claims were recorded per 1,000 passengers in November, compared with 6.94 in October, the department said.

American Airlines had the best on-time record for the third straight month, with 83.2 percent of its flights arriving within 15 minutes of schedule. Delta Airlines replaced Pacific Southwest as the worst performer, with 70.1 percent of its flights on time.

Among the 27 largest airports, John F. Kennedy International in New York recorded the worst on-time performance, with only 59.7 percent of arrivals on time. Washington National, the only local airport included, showed 72.5 percent of its flights arriving on time.

Any flight arriving within 15 minutes of schedule is deemed to be on time, and delays caused by mechanical problems are not included in the report. Under the department's performance disclosure rule, issued in September, the 14 largest air carriers must report their on-time records at the 27 largest airports, but the carriers voluntarily provide information on connecting flights as well.

"While poor weather may have affected the overall on-time performance during November, I am concerned about the increase in delays from the previous month and will continue to closely monitor airline performance records to see where improvements still need to be made," Transportation Secretary James H. Burnley said in a statement.

There were 71 chronically late flights in November -- flights that are late at least 80 percent of the time. One flight, Delta 943 from Cincinnati to Jackson, Miss., was late each of the 28 times it flew.

The DOT noted that since late December, consumers have been able to obtain on-time performance information for specific flights through airline ticket offices or travel agents.

The complaint data -- which was for December, traditionally a high-complaint month because of the heavy holiday travel -- covers such items as overbooking, baggage handling, reservations and ticketing, and customer service. The report showed Continental Airlines with the worst record at 18.7 complaints per 100,000 passengers, followed by Northwest at 15.78 and Eastern at 14.28.

The same three topped the complaint list for the previous month, with Northwest in the lead and Continental and Eastern following.

Continental and Eastern are both owned by Texas Air Corp. Those carriers and Northwest have been involved in large mergers, and the reports indicate that they continue to have problems as a result.

Overall, Southwest Airlines appeared to have the best record. The carrier was second to American in on-time performance, next-to-last in lost-baggage claims at 4.65 per 1,000 passengers (only Pan American World Airways at 3.13 was better), and was third from last in consumer complaints with 1.37 per 100,000. Aloha Airlines was best in that category at 0.38.