Minnesota Orchestra musicians have called for an independent audit of the organization's finances, including its endowments.

The request came in a letter from chief union negotiator Bruce Simon to Paul Zech, counsel for the orchestra board's bargaining team.

Simon's letter also expressed anger that the orchestra has gone public with a contract proposal, summary statement and financial information.

In a statement, orchestra management said: "We've answered these questions many times in our negotiations sessions, so we have no specific comment today."

The health of the orchestra's endowments -- a nest egg of investments that provide both ongoing revenue and a safety cushion -- is a key factor in the negotiations that are headed for a Sept. 30 deadline. Board and management contend that continued withdrawals are not a sustainable way to cover deficits.

Simon's letter hints that management alters its message about finances, depending on who is listening -- "donors (who you do not want to be frightened by a high deficit) or the orchestra's musicians (who you do not want to be emboldened by a lower deficit)."

The union, according to Simon's letter, wants details regarding: "$150 million-plus in traditional endowment funds, the recently revealed new endowment fund of $20 million, the tens of millions of dollars of additional pledges and bequests not reported as part of your endowment funds and the process by which the board determines the annual draw from various endowment funds."

On Wednesday, the orchestra posted several documents related to the negotiations -- an unprecedented degree of public transparency. Management has proposed cutting average musician salaries to $89,000, a reduction of 34 percent from the current $135,000. Base minimums would be cut to $78,000, down 28 percent from the current $109,000.

Doug Wright, a member of the union committee, took note of those proposals and also the orchestra's acceptance of $14 million in state bonding money for a remodeling project at its Minneapolis concert hall.

"At a time when millions of tax dollars are being invested in the renovation of Orchestra Hall and musicians are being asked to sacrifice over 30 percent of their income, we believe the public, our fans and the legacy of the orchestra will be well-served by a joint independent financial review," Wright said in a statement.

The next negotiating meeting is scheduled for Sept. 24.

Graydon Royce • 612-673-7299