Most major servicers reported increases in mortgage delinquency rates during the fourth quarter of 2011, but some industry data suggest seasonal factors influenced the increase. According to the Inside Mortgage Finance Large Servicer Delinquency Index, 10.88 percent of loans serviced by 19 major companies were in some stage of default at the end of 2011. That was up from 10.70 percent at the end of September and marked the fourth consecutive increase in the index. The biggest increase was in the serious default category, loans 90 days or more past due but not yet in foreclosure. Some 3.27...(Includes one data chart)