The contract with an unnamed state-owned Chinese shipyard comes just three weeks after the Bermuda-registered company paid $342 million for two 13,800-TEU 2010-built vessels that are on charter to French ocean carrier CMA CGM.
The company said the four new vessels, which are due for delivery in 2013, will be chartered on a time charter basis to "a large European-based container line" for seven years at a net daily rate of approximately $26,250.
SFI Chief Executive Officer Ole Hjertaker said the four ships will add around $270 million to the company's charter backlog which currently stands at more than $7 billion.
The company's 72 ship fleet comprises 11 container vessels, including five on charter to US-flag Horizon Line.