Under Armour Inc. will issue 400 million shares of a new Class C nonvoting stock to shareholders to update its capital structure and help keep its founder, Kevin Plank, in control.

The issuance of the shares will have the same effect as a 2-for-1 dividend to holders of Under Armour’s 400 million shares of Class A voting stock, but the new shares will trade under a different ticker than Under Armour’s “UA.” The record date for the distribution hasn’t been determined, but would follow approval of a series of changes to Under Armour’s charter at a special meeting of stockholders expected to be held on Aug. 26.

Plank, who is also chairman and chief executive officer of the Baltimore-based company, owns 35.7 million shares of Class B stock, each of which has 10 times the voting power of the Class A shares. He has agreed to back the plan developed by a special committee made up of independent directors.

“Our current dual-class voting structure is set to end when I own less than 15 percent of our total Class A and Class B shares outstanding,” he wrote in a letter to shareholders. “Dilution from regular employee equity-based compensation and other possible dilution, such as stock-based acquisitions or equity financings, as well as any sales of stock by me, bring us closer to this 15 percent sunset provision and could ultimately undermine our current governance structure.”

The issuance of the Class C shares, although carrying no voting weight, will give “investors twice the number of shares they had before. This is effectively a 2-for-1 stock split, something we have done twice in the past three years, though not with a new class of stock.”

As of March 13, when Under Armour released its definitive proxy to the Securities and Exchange Commission, Plank owned 16.8 percent of the total shares outstanding but, with his sole ownership of the Class B shares, holds 66.9 percent of the company’s voting power.

Plank pointed out in his letter, “My personal long-term financial success does not come from my compensation as ceo, but is driven almost entirely by the performance of our stock.” Although he receives stock awards and cash bonuses, Plank’s annual salary is just $26,000.

In connection with the changes in Under Armour’s structure, Plank has agreed there will be a cap on the number of shares he can sell in any year while the dual-class voting structure is maintained, and the multiclass structure would end in the event of his departure from the company.

He also signed a non-compete agreement that would remain in force for five years if he were to leave the firm.