The Securities and Exchange Commission has been trying for four years to convince investors and critics that it’s back on the beat.

As part of that effort, the agency has cited a record number of enforcement actions over the past two years — 734 in fiscal 2012 and 735 the year before — as evidence that an overhaul of its investigative forces has made the regulator smarter, faster and more effective.

“The sustained high-level performance comes two years after the division underwent its most significant reorganization since it was established in the early 1970s,” the SEC said in a November statement when it released the tally. “The results in 2012 were aided by many of the reforms and innovations put in place in the past two years.”

However, an analysis of that data by Bloomberg shows that the SEC filed fewer new actions last year compared with 2009, the year before it reorganized. The agency didn’t surpass those levels in 2011 either.

About 228, or 31 percent, of the 734 enforcement actions were “administrative proceedings” that instituted penalties in cases that already had been brought, sometimes years earlier. Examples of administrative actions include barring people who’ve already been found guilty of fraud from working in the industry, or temporarily suspending accountants from practicing before the SEC.

Excluding such follow-on proceedings, the SEC filed 506 original actions last year, fewer than the 520 it filed in 2009, the year before the reorganization. In 2009, 144, or 22 percent, of the 664 total actions were follow-on proceedings.

“The SEC is the only federal agency that can kick bad actors out of the securities industry,” SEC spokesman John Nester said in an e-mail. “These proceedings are fiercely contested, but it’s hard to see how investors would benefit if we won a fine in court but let the person go on cheating customers.”

When the SEC announced the results in November, then-Chairman Mary Schapiro cited the “innovative reforms” for the results.

“We’ve now brought more enforcement actions in each of the last two years than ever before, including some of the most complex cases we’ve ever seen,” she said.

The agency did order $3.1 billion in financial penalties and disgorgement of illegal profits in fiscal 2012 compared with $2.4 billion in fiscal 2009. Investigators in specialized units set up under Schapiro also have brought novel electronic trading cases.

However, the number of actions was buoyed by the most “delinquent filings” cases since at least 2006. Those cases often entail sanctioning or delisting companies that have stopped filing public statements. Typically, they require little investigation compared with securities-fraud cases and aren’t related to the overhaul of the division.

Stock manipulators have used securities with delinquent filings to hype the price before selling the shares into the artificial demand they created, Nester said.

“Rather than wait until investors lose their money, we take the securities off the market before innocent investors are ripped off,” Nester said.

Taken together, follow-on administrative proceedings and delinquent filings cases made up 48 percent of the enforcement division’s actions in fiscal 2012, compared with 36 percent in fiscal 2009, before the enforcement division was reorganized. At the same time, the SEC brought the fewest number of accounting-fraud cases since at least 2003.

In addition, the SEC issued 479 formal orders of investigation in fiscal 2012, down from 496 in fiscal 2009. A formal order authorizes staff to compel testimony and issue subpoenas.

The SEC has struggled for more than four years to beat back criticism that isn’t up to the job of policing markets. Lawmakers, investors and judges have faulted the agency for missing Bernard L. Madoff’s multibillion-dollar fraud and for not being tough enough on Wall Street for misconduct that helped fuel the financial market turmoil of 2008.

Schapiro, who was succeeded as chairman by Elisse Walter in December, took over the agency’s helm in 2009, just after Madoff’s fraud was exposed. To remake the enforcement division, she tapped Robert Khuzami, who eliminated a layer of management and established specialized units in 2010 to focus on areas such as hedge funds, market abuse and structured products.

— Bloomberg News