WASHINGTON — Republican Sen. Olympia Snowe remains by far the wealthiest member of Maine’s congressional delegation, but the financial portfolio of Snowe and her husband, former Republican Gov. John McKernan, declined last year.

Snowe’s personal financial disclosure report filed this week with the Senate secretary’s office shows a drop in the value of stock McKernan holds in Education Management, the Pittsburgh-based for-profit college company for which McKernan is chairman of the board.

The Justice Department has filed notice that it would intervene in a whistleblower lawsuit alleging the company improperly compensated employees who recruit students. The company operates institutions in 31 states and Canada, none in Maine.

A GOP primary challenger to Snowe as she runs for a fourth term next year, Scott D’Amboise of Lisbon Falls, last week cited the case in calling on Snowe to resign.

In response, Snowe said that neither she nor her husband had done anything wrong and charged D’Amboise with running a “libelous” smear campaign. Snowe also said she has no involvement with the company.

The company has denied any wrongdoing.

In her personal financial disclosure report covering 2009, filed last year, Snowe valued her husband’s stock option agreement in Education Management at $1 million to $5 million, while his common stock holdings in the company were valued at $5 million to $25 million.

In the report filed this week covering 2010, the stock option agreement remained at $1 million to $5 million, and the common stock holdings were reduced to $1 million to $5 million.

The ranges make it difficult to determine how much value McKernan’s common stocks lost. Education Management spokeswoman Muller said the loss is not as big as the broad ranges might suggest.

“The value for 2009 was closer to $5 million than $25 million, thus the move to the $1 million to $5 million range is not as big a shift as might be interpreted,” Muller said.

Education Management’s stock price is in the $20 to $22 per share range currently, but it dipped last fall to about $8 per share, according to NASDAQ market figures. Its 52-week high was nearly $23.50.

Snowe and her husband own other valuable investments, including a tax-free money market fund valued at $1 million to $5 million. They also have a stock fund valued at $500,000 to $1 million and a number of other stock and bond funds valued in the low to mid-six-figure ranges.

The personal financial disclosure reports were due Monday, but aren’t officially released to the public until next month. All four members of the Maine delegation, when asked by MaineToday Media, provided their reports. Not included are personal residences, which are exempt.

Sen. Susan Collins, R-Maine, lists two IRA funds each worth $50,000 to $100,000 as her most valuable assets.

Rep. Chellie Pingree, D-1st District, lists as her sole asset, worth $500,000 to $1 million, the Nebo Lodge, an inn and restaurant she owns in North Haven. Pingree is engaged but not yet married to billionaire hedge fund manager S. Donald Sussman, who owns a house in Maine.

Rep. Mike Michaud, D-2nd District, lists a half interest in three rental properties, two in East Millinocket and one in Augusta, each valued at $50,000 to $100,000, along with some investment funds, most valued at $1,000 to $15,000 each.

MaineToday Media Washington Bureau Chief Jonathan Riskind can be contacted at 791-6280 or at: [email protected]