Stock market opportunists are hovering around IAG in the latest attempt to separate shareholders from their shares.

IAG told its shareholders last week to reject an unsolicited bid from Share Buying Group of $2.67 per share, well below the company's trading price of $4.89 at the close of business.

The man behind the bid, listed company director Patrick Dromi, has also sent offers to Adelaide Bank shareholders.

In March, Share Buying Group offered Bendigo Bank shareholders a similarly undervalued bid for their shares.

IAG Head of Investor Relations Mike Woods says if shareholders want to sell, they should do so on the Australian Stock Exchange.

The offer is the second time in four months IAG shareholders have been approached by share market opportunists modelled on infamous trader David Tweed.

In July, IAG warned shareholders that a company called Share Buyback Group had requested a copy of the company share register.

The Australian Securities and Investments Commission barred the group from making any more offers. However, it is believed the group then launched a new company, known as Hassle Free Shares, under the same ownership.