Profitability of the Through Transport Mutual Insurance Association (TT Club) has taken a knock from an increase in larger claims in a period of marginal investment returns.

The club reports a $2.2m surplus for the first eight months of the year in a trading update. This is down on the $5.7m rung up through the same period of last year and $14.1m through the full 2014 year.

The liner shipping insurance club reports that claims included seven costing more than $1m between the New Year and the end of August. This includes the catastrophic explosion at the Chinese port of Tianjin expected to produce the biggest claim of the year.

Chief executive, Charles Fenton, warns that the increase in large claims will result in a higher combined ratio - where bigger is worse - but still below the 100% break even level.

“The performance of attritional claims has been largely as expected. However large claims have increased in number,” Fenton added.

The investment return through the first eight months was just 0.1%, down from 1% at the same stage of 2014.

The 'A-' rated mutual earned a gross premium of $116m through the first eight months of 2015, down from $121.4m through the same period of last year.

The free reserve increased to $177.9m from $175.7m at the start of the year and $167.4m a year ago.

The TT Club, set up in the early days of containerisation, has shipowner members who include AP Moller-Maersk, Cosco, Hapag-Lloyd, Evergreen, OOCL, K Line, Pacific International Lines, Grindrod, DFDS and Atlantic Container Lines.

There is also a substantial port, logistics and freight forwarding membership.