RESEARCH TRIANGLE PARK — Public companies’ required securities filings sometimes make for very interesting reading.

Nortel stock trading by senior executives is a hot topic right now, given the financial problems that are rattling the network giant and have triggered firings, suspensions, restatements of earnings plus a rash of investigations — internal and external.

The numbers cited here are from data provided at Yahoo!’s financial web site.

Nortel insists the stock awards were based on company performance. These transactions were made on Feb. 3.

The stock price ranged from $6.36 to $8.06. Nortel stock now trades at 3 bucks and change. Some 3.7 million shares were awarded to this group, and 2.69 million were sold — immediately — with a value of at least $17 million and as much as $21 million.

The February trades followed a round of awards to the execs in July of last year when the stock was trading at under $3. Frank Dunn, the fired chief executive officer of the company, reaped $999,231 last July.

Executive’s name; shares acquired; shares sold; minimum value:

Brian McFadden – 372,500; 276,060; $1.75 million

Susan Spradley — 287,500; 196,147; $1.24 million

Malcom Collins — 267,500; 188,588; $$1.19 million

Stephen Pusey — 310,000; 218,550; $1.38 million

John Granatteo — 150,000; 106,088; $674,000

Robert Mao — 215,000; 146,684; $928,560

Dion Ivannou — 150,000; 102,338; $648,720

Michael Gollogly — 97,500; 71,375; $451,560

Masood Tariq — 267,500; 193,537; $1.22 million

William Donovan — 215,000; 155,553; $985,800

Nicholas Derma — 267,500; 195,824; $124,020

Katharine Stevenson — 97,500; 71,375; $451,560

Pascal Debon — 372,500; 254,139; $2.36 million

D. Gregory Mumford — 287,500; m210,465; $1.33 million

Charan Bolouri — 267,500; 198,245; $1.26 million

Steven Schillmg — 150,000; 108,525; $686,880

Here are the money amounts made by these folks based on stock awarded on July 28 of last year and sold on July 29:

McFadden – $519,000

Spradley – $305,000

Collins – $320,000

Pusey – $127,000

Gianatteo – $181,000

Mao – $228,000

Ivannou – $159,000

Gollogly – $210,000

Tariq – $349,000

Donovan – $280,000

Derma – $358,000

Stevenson – $130,000

Debon – $396,000

Mumford – $385,000

Bolouri – $372,000.

Canadian authorities banned Nortel execs from trading stock on Monday after the markets closed.