Claus-Peter Offen is pushing ahead with another major vessel transaction with Tufton Oceanic — this time in container shipping.

The German owner is believed to have sold a pair of 9,200-teu boxships to the UK-based private equity operator in a deal likely to top $40m.

The value of the deal could be significantly more as it probably includes a charter to Mediterranean Shipping Co (MSC).

Speculation is that the ships involved are the 9,178-teu Santa Lucilla (built 2007) and sistership Santa Louisa (built 2006), which operate as the MSC Lisbon and MSC Roma.

Ownership of the vessels, renamed BSL Lisbon and BSL Roma, changed this month, although the management remains with Claus-Peter Offen, according to Equasis data.

Offen controls two sister vessels, the 9,200-teu MSC Chicago and MSC Bruxelles (both built 2005), which are also on charter to MSC.

The acquisition of neo-panamax containerships would be by far the largest in the Tufton fleet, which has been limited to seven sub-panamaxes between 2,500 teu and 2,800 teu. That includes the 2,782-teu newbuildings Porthos and Aramis, which are slated for delivery from Jiangsu Yangzijiang Shipbuilding in China. It also owns the 2,500-teu BSL Limassol (built 2002) and BSL Cape Town (built 2003).

Tufton is acquiring the ships at a time when values for the traditional post-panamax design have fallen to between $18.8m and $19.6m each — or less than half their value a year ago, according to VesselsValue estimates.

The deals mean that the Offen Group has probably raised around $100m on vessel sales in the past six months.

This includes around $35m reportedly raised for the sale to Tufton Oceanic of the 52,000-dwt tankers CPO Korea (built 2009) and CPO Japan (built 2010).

In February, Tufton Oceanic launched a $150m initial public offering on the London Stock Exchange in a play on second-hand vessels across market segments.

Andrew Hampson, head of asset-backed investments, was quoted at the time saying that Tufton was looking to buy assets at a significant discount to their depreciated replacement cost and lock in long-term employment.