The latest round of licensing for oil and gas operations in the North Sea and nearby waters is open for applications.
The Oil and Gas Authority (OGA) said a total of 813 blocks or part blocks are on offer in the UK Continental Shelf, offering firms a "significant opportunity".
The UK oil and gas regulator said blocks on offer in the North Sea, west of Shetland and east Irish Sea feature a "large inventory of prospects and undeveloped discoveries".
More than 114,400 sq km are covered by the latest licenses.
The OGA is providing information about the seabed to enable companies to identify opportunities.
OGA chief executive Andy Samuel said: "The 30th licensing round offers companies a significant opportunity to rebuild their portfolios; taking advantage of the flexible Innovate Licence, technology and improvements to the UKCS fiscal regime.
"These factors combined mean now is a very good time to invest on the UKCS.
"We are encouraging companies to take a fresh look at large areas of acreage, some of which has not been available since 1965, and make best use of the recently-released information and new data packs to inform their applications."
The round is open until November 21.