Lennar Corp. shareholder GAMCO Asset Management Inc. is proposing that the company's class B common stockholders be granted the right to convert their shares into class A common shares at any time.

GAMCO, which disclosed a 5.97% stake in Lennar in an Aug. 2 ownership filing, called on the board to take measures to implement the proposal that it planned to submit for the company's 2018 annual shareholder meeting.

GAMCO is making the proposal on behalf of investment advisory clients and related parties owning 3.4 million shares of Lennar's class B common stock, according to the filing.