Thai feeder operator Regional Container Lines has taken its tally of 4,400-teu boxships on order to six costing a total of $339.6m.

The Bangkok-listed company has declared an option on two more vessels at CSSC Huangpu Wenchong Shipbuilding in Guangzhou, China.

The vessels, costing $56.6m each, are slated for delivery in November and December 2027.

The deal adds to an order for an identical quartet at the yard towards the end of 2023, due for delivery beginning in the first quarter of 2027.

The ships will be able to use port electricity, resulting in a reduction in emissions during port operations.

They will be powered by conventional fuel but can be modified “to support alternative fuels and green power sources in the future”.

They will replace ageing vessels and modernise the fleet, offering fuel savings of up to 40%.

RCL is taking delivery of two 12,000-teu and four 7,000-teu newbuildings.

Japan’s Nihon Shipyard is building the larger duo for delivery this year.

China’s Shanghai Waigaoqiao Shipbuilding delivered the first of the 7,000-teu boxships, Guru Bhum, on 18 April.

The Guru Bhum and a sister ship have been chartered for two years to Singapore’s Pacific International Lines, for which it will operate as Kota Tema.

RCL was also reported to have chartered out the 12,000-teu duo to Pacific International Lines.

RCL is Thailand’s largest container line and ranks 24th globally, according to Alphaliner.

The intra-Asian operator maintains a fleet of 34 ships with a combined capacity of about 77,000 teu.

Profits halved after an impairment of THB 857m ($23.8m) in 2023.

Before the vessel impairment, the company logged a profit of THB 2.36bn, a decrease of 90% compared with 2022.

Net profit was THB 1.5bn.