(Sharecast News) - Shares in AIM-listed STM Group dropped on Tuesday morning after the financial services company once again extended its deadline to agree terms on a takeover by Pension SuperFund (PSF) Capital.

The companies announced back on 11 July that they had reached agreement in principle on the key terms of a possible cash offer for STM, which valued the company at 70p per share or £42m.

STM said at the time that, should a firm offer be made, it would "recommend it unanimously" to shareholders.

It had initially set an 8 August 'put up or shut up' deadline for a firm offer, which was then extended to 22 August. The company now says it has pushed this back again to 5 September.

"This deadline may be further extended with the consent of the [Takeovers and Mergers] Panel, at STM Group's request," the company said in a statement.

The shares were down 11% at 46.55p on Tuesday morning.