Michael Larson, the money manager of Bill Gates, launched a legal battle against a board member of Swiss chemical company for violating his fiduciary duties.

According to the Wall Street Journal, Cascade Investment LLC, the investment management firm controlled by Bill Gates and the Bill and Melinda Gates Foundation Trust disclosed its lawsuit against Urs Burkard, a director Sika AG, a Swiss chemical company.

Mr. Larson is the chief investment officer of both Cascade Investment LLC, and the Bill and Melinda Gates Foundation Trust. The entities have more than $120 billion in assets.

Sika AG Michael Larson

Details of the lawsuit against Sika AG board member

Sika AG is in the middle of a $2.9 billion takeover battle. Mr. Burkard is a member of the family that owns 16% of the shares of Sika AG and holds a majority voting rights in the Swiss chemical company.

Cascade Investment and the Bill and Melinda Gates Foundation Trust are minority shareholders with 5% stake in Sika AG. The entities also hold a 3% voting rights in the Swiss chemical company.

Mr. Bukard’s family reached an agreement to sell its stake in Sika Ag to Saint-Gobain in December. The deal gave Saint-Gobain a majority control of the Swiss chemical company without the need to buy out minority shareholders.

Mr. Larson believed that the deal between Mr. Bukard’s family and Saint-Gobain was “inequitable,” according to a person familiar with the situation.

Cascade Investment and other minority shareholders have been opposing the deal for months. The Swiss financial regulator ruled that Saint-Gobain is not required to make an offer to the minority shareholders of Sika AG.

Mr. Larson asked the Swiss court to review Mr. Bukard’s conduct

In its lawsuit, Cascade Investment accused Mr. Bukard of pushing the deal with Saint-Gobain despite a public statement that his family was committed to Sika AG. The investment management firm demanded a reimbursement of the expenses incurred by the Swiss chemical company related to the deal.

In a letter to Sika chairman Paul Haig, Mr. Larsom pointed out that Mr. Burkard should explain why he negotiated a deal that contradicted the interest of the company and its public shareholders. He should also explain why conducted the negotiation secretly, without consulting the rest of the board of directors.

Mr. Larson added that they asked the Swiss court to review Mr. Burkards Conduct as the architect of the proposed transaction and as a member of the board of directors of Sika AG.

Mr. Larson told Mr. Haig that Cascade Investment and the Bill and Melinda Gates Foundation initiated a director’s liability lawsuit against Mr. Burkard for violating his duties. The entities filed that case with the Justice of Peace in Baar, Canton of Zug.