Investors with the Dollar Thrifty Automotive Group have asked for a vote by shareholders over the Hertz takeover bid to be stopped.

The high-profile and protracted bidding war that has waged for months between Hertz and rival Avis, has left investors in the smaller Dollar Thrifty organisation dubious as to whether the company is getting true value for money under the Hertz deal.

Hertz made the initial offer of $1.1 billion back in April, when the troubled Dollar Thrifty shares were low and investors more welcoming of the potential acquisition. The offer also contained several clauses relating to other bidders and termination fees, which will see Dollar shell out millions should they choose to go with the $1.3 billion counterbid from Avis.

Lawyers for disgruntled shareholders, who have seen their stocks rise significantly during the negotiations, claim the company had been too eager to accept the Hertz bid, the price of which they claim is ‘terrible’. They have asked Delaware Chancery Court Judge Leo Strine to halt the vote until regulators complete a review of the Hertz buyout.

The shareholders’ lawyer have also suggested that the board at Dollar Thrifty is involved in a conflicts-of-interest problem after it was revealed they were being advised by bankers from JPMorgan Chase & Co and Goldman Sachs, with allegations that both have close links to Hertz and a vested interest in seeing the deal proceed.

Dollar Thrifty has become an increasingly attractive target as it rebounds from the recession, though regulators are still to approve whether any takeover may lead to the successful bidder gaining market control.