MONTREAL -- The founder and CEO of Gildan Activewear is once again selling a big block of his shares in the apparel manufacturer.

Glenn Chamandy has entered into a plan with a Canadian financial institution to sell up to four million of his common shares in the Montreal-based company over the next year.

The shares are worth more than $170 million.

Even after the sale, he would remain one of the company's largest investors, with more than 8.4 million shares valued at about $362 million.

Chamandy has put up large blocks of shares in Gildan for sale on three previous occasions.

In 2014, he sold one million shares. Two years earlier he announced plans to sell up to 2.75 million shares. In 2007, he sold 3.6 million shares for diversification and estate planning purposes.

Under U.S. and Canadian securities laws, company insiders can sell shares over a predetermined period of time and subject to predetermined volume and price parameters.

The plan can only be established when the insider is not in possession of material non-public information.

Once a plan is established, Chamandy has no discretion over sales under the plan.

Gildan manufactures T-shirts, fleece, socks and underwear at low-cost manufacturing sites in Central America, the Caribbean Basin and Bangladesh. It has more than 42,000 employees around the world.