GasLog Ltd has sold its 170,000cbm LNG carrier Methane Julia Louise to a subsidiary of Mitsui Co Ltd and will lease the vessel back on a bareboat charter of up to 20 years.

No specific price for the vessel was disclosed, but Gaslog said that the consideration was "approximately equivalent to its current book value" and has used US$50.6m of the proceeds to prepay part of the vessel's $230m debt. VesselsValue.com estimates the ship's current market value at some US$160.84m.

GasLog has the option to re-purchase the vessel on pre-agreed terms between the end of year 10 and the end of year 17 of the bareboat charter.

"The transaction we announced with Mitsui may open up further commercial and financial opportunities for GasLog in the Japanese financing market," Paul Wogan, Gaslog's CEO, said in the company's financial results for the fourth quarter and fiscal year 2015.

Methane Julia Louise was acquired for $230m by Gaslog from Methane Services (MSL), part of BG Group, in December 2014. The vessel was then chartered back to MSL on an 11-year timecharter, plus a three- or five-year extension option.