Two major Singapore marine and offshore service providers have clinched significant new orders.

Yangzijiang Shipbuilding, a mainboard-listed shipbuilder, said it won new contracts for four bulk carriers, and converted 13 options for bulk carriers and containerships into effective orders last month.

The total value of these 17 orders is about US$871 million (S$1.1 billion), it said in a filing to the Singapore Exchange (SGX) on Tuesday. The vessels are due for delivery in 2015 and 2016.

Further, the new contracts for four bulk carriers come with options for two identical vessels, Yangzijiang added.

In the third quarter of this year, the company secured 25 shipbuilding contracts totalling US$1.1 billion, bringing its total contracts so far this year to 52, worth US$2.1 billion in all. Yangzijiang also has 28 outstanding options for additional vessels with a total value of US$1.36 billion.

Separately, Keppel Fels said on Tuesday that it has been awarded a contract to build a pair of jackup rigs for an affiliate of Clearwater Capital Partners, an investment management company.

The cost of the project will be about US$440 million and the rigs are scheduled for completion in the fourth quarter of 2015 and the first quarter of 2016, said Keppel Fels, which is wholly owned by Keppel Offshore & Marine (Keppel O&M), a subsidiary of Keppel Corporation.

"Having delivered 16 rigs already this year, Keppel Fels has demonstrated its strong project execution capabilities in completing all its projects safely, ahead or on time and within budget," said Mr Wong Kok Seng, managing director (offshore) of Keppel O&M and managing director of Keppel Fels.