Seven, which has established its Seven Energy spin-off with unconventional assets in the US, and Gippsland and Browse basins in Australia is believed to be considering a consolidation strategy of the bigger Cooper Basin juniors.

Beach, through its own exploration efforts and its purchase of Delhi Petroleum a few years back, is one of the main drivers of exploration and development in the basin.

Yesterday Seven moved up from 13.79% to 16.24% with the addition of 41 million new shares, 20 million of which came from James Packer's former associates at Ellerston Capital.

Ellerston still holds 9.09% of Beach.

Seven has been buying into Beach since March 11, paying between 94 cps and $1.17/share as Beach's value has risen.

In Drillsearch Seven has upped its stake from 16.69% to 18.86%, paying $1.28 per share for the latest 10 million shares.

It is clearly close to the 19.9% cap which would require Seven to declare a takeover offer for either company, but of course Seven might merely wish to have a seat at the table, although there is some question about how Seven might fund a takeover.

Private equity is one suggestion.

Seven is also believed to hold a small parcel in another Cooper Basin oil producer, Senex Energy, and well a number of holdings in listed oil and gas companies for general investment.

Publicly Seven says that it has no takeover ambitions, but market rumour is that the company plans to bring former Woodside Petroleum boss Don Voelte back to run its energy unit.

Until recently, Voelte was a Seven director.