Woodside was known to be shopping for a suitable ­design for a semi-submersible drilling unit to go on a long-term charter at Browse.

Norwegian player Seadrill, Denmark’s Maersk Drilling, New York-listed Parker Drilling and Houston-based ­Atwood Oceanics were said to have teamed up with par­ticipating yards to jointly propose rig designs and submit charter dayrates earlier this year.

The newbuild cost estimates came up to about A$340 million ($332 million) and the ­proposed charter dayrates to about $350,000, sources said.