Investment business Rubicon has received a partial takeover offer from US-based Knott Partners.
Knott Partners together with associated funds, already owns 18.5% of Rubicon, and wants to lift its stake to just over 27%.
It is offering 70 cents a share, a premium of 27% on Monday's closing price.
Knott Partners principal David Knott already owns 1% of Rubicon himself, so the group would control 28.3% in total.
Because the offer is for less than half of Rubicon, Knott must get majority shareholder approval.
Rubicon's board is telling investors to wait for its independent appraisal report on the offer, and the directors' recommendation.
Rubicon has a one-third stake in forestry biotech group ArborGen, which is expanding its business to enter the biofuels sector, and a 58% stake in struggling US-focused wood products company, Tenon.
At its annual meeting earlier this year, Rubicon told shareholders that if ArborGen and Tenon were successful, the company would more than meet its target shareholder return of 17% per annum over the company's life.