Global Ship Lease (GSL) is putting up for sale $5.75m worth of shares eight months after acquiring Poseidon Containers in a $780m deal, including debt.

The Ian Webber-led boxship owner in May ultimately registered 20.4 million shares for sale that were given to Poseidon Container Holdings and K&T Marine in exchange for 19 boxships, doubling GSL's fleet, according to SEC filings.