Experian reports that businesses with one to four employees had the greatest shift in percentage of dollars considered severely delinquent.

According to Experian's Business Benchmark Report, that shift went from 9.9% in June 2010 to 11.7% in June 2011. The firm defines severely delinquent as more than 91 days late.

Very large businesses, which are those with more than 1,000 employees, had the greatest shift in percentage of dollars delinquent, going from 11.6% in June 2010 to 18.2% in June 2011.

The greatest improvement in percentage of dollars delinquent and severely delinquent came from businesses with 100 to 249 employees, the data showed. Those businesses reduced their debt by 7.3% and 35.8%, respectively, year over year, Experian reported.

All business sectors showed an increase in slow payment in a year-over-year comparison. The largest increase in slow payment came from the construction industry at 17% and insurance industry at 15.7% when compared with June 2010.

The utilities, insurance, legal services and health services sectors improved their debt days beyond term by 2.9%, Experian said.