If you thought that underhand off-market share buyback players would crawl back into the woodwork during the current market environment, you were wrong. It seems there's no time like the present uncertainty to take advantage of some shareholders.

If you're fortunate enough to have never had an off-market offer for your shares - here's how they usually work.

A group with a name such as Share Express, Share Buyback Group or David Tweed's Direct Share Purchasing Company approaches a company for its share registry.

As it is a public document, the company is required to provide the information, which has the details of every holder of every share.

The buyback operator then sends out letters offering to buy those shares at below the market price. For example, an offer was made earlier this year for Ruralco unitholders for $1.92 a share when they were trading at more than $4.

In the midst of the short-selling ban and the confusion that followed last week, Perpetual issued a warning to shareholders that they might soon receive a letter from one of these operators - Hassle Free Share Sales Pty Ltd.

Hassle recently sought a copy of Perpetual's shareholder register and Perpetual had provided it.

"Perpetual must maintain a register of its shareholders in accordance with the Corporations Act. This is a public document and we cannot prevent any party from either reviewing or seeking a copy of our register," Perpetual company secretary Joanne Hawkins said.

Perpetual was starting on the front foot and was hoping it would get to its equity holders before Hassle did. It provided a link to the Australian Securities and Investments Commission consumer awareness site Fido and told shareholders where and how to find the market price of Perpetual shares.

Off-market buyback share players will target companies whose share prices have risen greatly in value and those that have been demutualised, that is, many of their shareholders have not bought the shares on market but received them as policy holders.

If you do receive a letter, the company is required by law to provide:

? a written statement setting out the market value of those shares on the day the offer is made; and

? a minimum of one month in which to accept the offer.

If they do not provide the market price, they can face a fine of $22,000 or two years' jail for each breach.

You can find daily share prices on the ASX website at http://www.asx.com.au. Even if you don't know the ASX code of your company, you can enter the company name.

Don't accept an offer at well under market price and don't believe anyone who tells you stockbrokers are expensive. They can be, but online or telephone non-advising brokers will sell your shares for between $30 and $70 a parcel, so if you need the money you don't need to accept an off-market offer.

There is always a reason why someone is sending you these share offers, and these players generally operate on the assumption that some people will not be aware of what's happening with their company, so check the ASX announcement updates as well.

And always remember - if something sounds too good to be true, it usually is.