Containership leasing giant Seaspan Corp is continuing a revamp of its balance sheet by using cash to redeem some $300m in bonds.

Seaspan, a subsidiary of New York-listed Atlas Corp, said the 5.5% senior notes include $250m due in 2025 and $50m maturing in 2026. All are held by backer Fairfax Financial Holdings.

"We are very appreciative of our partnership with Fairfax and the strong support they have provided," said Atlas chief financial officer Graham Talbot.