The number of companies that were late with their 2005 filings to the Securities and Exchange Commission fell 30 percent, to 203, from the year before, according to a recent report published by Glass, Lewis.

The proxy-research firm also found that only 63 late filers cited incomplete internal-control work as a reason for delaying the release of their annual reports — less than half the 138 companies that cited that as a reason for delaying their reports in 2004 (the first time such assessments were required). The study examined companies with market capitalizations of $100 million or more that report on a calendar-year basis.

But these numbers don’t necessarily suggest that Corporate America’s ability to close its books on time has improved. The number of late filers still was more than triple the number for 2003 annual reports. And the number of serial late filers is swelling.

According to a separate Glass, Lewis study put together for USA Today, more than 100 companies that did not file their 2005 financial statements on time were also late with their numbers the year before. That’s twice the number of companies that were late completing both their 2004 and 2003 reports.

What’s more, 23 companies have been late for three straight years, including Nortel, Flowserve, Shurgard Storage, and Kansas City Southern, according to the paper.

“If you get three speeding tickets in a year, in many states you get your license pulled,” Mark Cheffers of AuditAnalytics.com told USA Today.

The research firm noted 15 companies that delayed their annual reports two years in a row but, as of the date of their late-filing notices, had not reported any material weaknesses. “We believe these companies’ financial-reporting controls likely are not up to par, notwithstanding management certifications that they are effective,” the report added.