Australian firm Oilex has extended its exclusivity agreement with Koru Energy for the purchase of East Irish Sea assets until the end of October.
The agreement, first announced on September 15, was set to expire on September 30.
The deal covers 50% of the Knox and Lowry, and Whitbeck gas discoveries.
They are close to a subsea tie-back pipeline which delivers gas to the recently refurbished North Morecambe platform and terminal.
Oilex is registered in Perth, Western Australia, and is listed on the London and Sydney stock exchanges.