An activist investment firm filed a preliminary proxy with Imation Corp. shareholders and regulators Thursday, alleging mismanagement and outlining why it wants to nominate three candidates to the data storage company's board and slash executive and director pay.

The filing seeks the support of shareholders of Oakdale-based Imation against the wishes of Imation's management. It is the second run at a Minnesota company by the Clinton Group, a New York investment firm with $1.5 billion in assets under management.

Last year, it won control of the board of ValueVision Media Inc. of Eden Prairie in a similar proxy battle.

In December, Clinton officials informed Imation's board that they want to choose three Imation board members this spring, when three of six board members are up for re-election.

Thursday's filing made Clinton's December salvo official and set the stage for a new proxy fight at Imation's annual meeting on May 20.

In its filing, the Clinton Group said "We believe there are systemic issues with the company's leadership today. In the board of directors' room the company's fiduciaries appear to believe they are truly doing what is right for shareholders, although financial results and stock price performance would indicate other wise."

The SEC filing cited Imation's financial losses, stock declines and struggling acquisitions. It alleged excessive compensation and mismanagement and proposed slashing board members' total fee and stock compensation to $50,000 a year, down from last year's average of $350,000.

Clinton senior portfolio manager Joseph De Perio told the Star Tribune in an interview, "The board's views on compensation … would suggest that they believe they are doing a great job, which we believe is diametrically opposed to any data we have examined on historical stock price performance and financial performance."

Imation, a data storage firm that spun off from 3M Co. in 1996, said last month it lost $114.7 million in 2014 as revenue declined 15 percent, to $729.5 million. Imation's stock is trading around $4 a share, down from the 52-week high of $6.29 and far from its $12.36 price in January 2011.

Imation CEO Mark Lucas recently told Wall Street analysts that Imation hired investment bankers and is exploring "all options" for the struggling firm.

He added that he was frustrated that attempts to negotiate with the Clinton Group proved unsuccessful and that Clinton officials declined to say what they wanted Imation's management to do differently.

Lucas on Thursday told the Star Tribune in a phone interview that he was pleased to finally hear something from Clinton.

Still, he said, "The Imation board of directors and management team remains committed to driving value for all shareholders and will continue to execute our strategic plan while exploring alternative ways to unlock the value of our businesses."

Lucas said he and his team will review Clinton's recent filing, but said, "We sincerely hope [the Clinton] shareholders don't hinder our efforts to explore alternatives and create value for all shareholders."

Clinton's proxy solicitation nominated three people to Imation's six-member board: De Perio; data storage executive Robert Fernander; and Barry Kasoff, president of Realization Services Inc.

The group also hopes to appoint a chief restructuring officer to oversee Imation's traditional data storage business.

Imation makes consumer and commercial data storage devices such as recordable CDs, DVDs, Blu-ray optical discs, flash drives, tapes and external hard drives.

In 2006 and 2007, Imation bet its future on the key acquisitions of Memorex and the recordable media business of Japan-based TDK. Both deals, worth $590 million combined, greatly expanded its consumer data storage division.

But since 2010, technology has changed and CD and DVD use has declined. New acquisitions included the $118 million purchase of hybrid disk-storage firm Nexsan and several smaller purchases of data security system companies, the filing said.

Lucas told analysts that Imation is making progress in growing its data security business, but said, "we recognize we have much more to do as we position the business for consistent and sustainable growth."

He added that the company introduced new, higher-margin data-storage products, lowered expenses and moderated declines from its legacy tape, CD and DVD storage businesses. The changes take time, Lucas said.

But investors may be losing patience.

In December, New Orleans-based Spear Point Capital Management demanded that Imation take action to create shareholder value, slash compensation, appoint new board members and improve results.

While recent acquisitions were expected to boost results, the Clinton proxy said Imation's sales fell 43 percent to $729 million between 2010 and 2014. Gross profit fell 35 percent to $138 million during the same period.

Clinton's proxy blamed the poor results on Lucas and Imation's nonexecutive chairman, L. White Matthews III. The proxy paired the decline of Imation's stock price and profits with the tenure and compensation of both leaders.

De Perio said that if Clinton wins the three seats it seeks, the outside voices can positively influence the direction of the manufacturer.

With the official filing of Clinton's proxy, Imation shareholders will get to vote on the issue during Imation's May 20 annual meeting.

In a note to clients, equity researchers at Lake Street Capital Markets said that the Imation proxy solicitation was expected for a long time. Like both sides in this proxy battle, "We also see untapped value in Imation stock and believe long term shareholders should benefit, regardless of who wins the proxy contest," Lake Street analysts said.

Shares of Imation closed Thursday at $4.01, down 4 cents a share.