Seadrill Ltd. and the Daewoo Shipbuilding & Marine Engineering (DSME) shipyard have agreed to defer the delivery of two ultra-deepwater drillships, the West Aquila and West Libra, until second-quarter 2018 and first-quarter 2019 respectively, Seadrill said in a news release.

Under the terms of the original construction contracts, Seadrill said the units were to be delivered by the end of second-quarter 2016, and the total final yard installment for both units of over $800 million was due at that time.

By deferring these capex commitments to 2018 and 2019 with no further payments to the yard until that time, Seadrill was able to improve its near-term liquidity position, the company said.