SINGAPORE, June 4 (Reuters) - Singapore's Keppel Corp , the world's biggest maker of offshore oil rigs, said on Thursday it is prepared to help in the restructuring of a customer that has placed orders worth about S$1.7 billion (US$1.18 billion).

Norwegian firm Skeie Drilling & Production had said on Tuesday it had missed payments on the rigs and was in breach of an agreement with bondholders.

News of Skeie's problems, reported in Singapore's Business Times on Thursday, helped push down Keppel shares by as much as 4.4 percent in early trading. Skeie shares tumbled 12.5 percent on Wednesday, and have slumped more than 96 percent in the last 12 months.

Skeie said in the June 2 announcement it hopes to get a majority of bondholders to approve a restructuring proposal by Thursday.

"Keppel FELS (a Keppel unit) is supportive of and participating in this restructuring exercise. Once two thirds of the bondholders agree, then the restructuring will proceed as stated," a Keppel spokeswoman said, adding that Keppel is proceeding with building the three rigs ordered by Skeie.

According to Skeie, its restructuring proposal involves Keppel agreeing to amend the rig order contracts, as well as commitments by Skeie's major shareholders Skeie Technology and Wideluck to underwrite US$85 million in new equity.

Keppel, which has a less than 10 percent share in Skeie, will also help underwrite the new equity, the Business Times reported.

DMG & Partners analyst Serene Lim said Keppel's earnings could fall by 3 percent this year and 8 percent next year if the restructuring proposal is rejected, and Keppel either stopped work on the rigs or completed them for sale to another party.

Skeie officials could not be contacted for comment.

(Reporting by Kevin Lim, Editing by Ian Geoghegan)