On Friday, Silver Lake lifted its bid from 0.27 of a Silver Lake share for every one EganStreet share held to 0.4 of a share for each EganStreet share held, valuing EganStreet at 46c per share.
It said if it reached a 38% interest in EganStreet by Friday, it would further lift the consideration to 0.431 shares for each share held, valuing EganStreet at 50c per share.
Silver Lake has gone from 31.5% last week to 40.05% as of this morning.
The company has declared the offer unconditional.
The offer will close on December 13.
The bid is unanimously backed by the EganStreet board.
EganStreet actually acquired its flagship Rothsay project from Silver Lake in 2011 for $1.2 million cash.
Silver Lake floated with the project back in 2007 but offloaded it after deeming it non-core.
Gold was discovered at Rothsay in the late 1800s and the project has historically produced around 54,000 ounces of gold.
It was last mined by Metana Minerals in the early 1990s, but production ended due to the weak gold price at the time.
An updated feasibility study for Rothsay, released in February, outlined capital costs of $55.8 million for a seven-year operation producing 289,000 ounces of gold at all-in sustaining costs of $1069 an ounce.
Rothsay has a resource of 454,000oz at 9.2 grams per tonne gold.
Silver Lake is planning to process Rothsay ore through its nearby Deflector plant, 85km to the north-west.
EganStreet shares rose 2% to 50c, while Silver Lake was up 0.9% to $1.155.