City lawyers have reacted with scepticism to the bid tactics being employed in the takeover battle between rival Midland brewers Marston Thompson & Evershed and Wolverhampton & Dudley.

The so-called 'Pacman' defence – when a firm counter-bids against the rival attempting to take it over – is being used by Marstons, advised by Linklaters, against Wolves, advised by a Freshfields team.

The tactic, named after the 1980s computer game, was widely used in the US during the early 1980s. Corporate lawyers believe this is the first time that the ploy has actually been implemented in the UK, although it has been threatened a couple of times.

Clifford Chance corporate partner David Child said the tactic amounted to an admission that a merger would be a good thing. "The main plank of a hostile bid's defence is usually to maintain independence so it can deliver shareholder value."

US-qualified lawyer Jeff Gordon, a partner at Mayer Brown & Platt's London office, said the Pacman ploy was largely discredited in 1982 when Martin Marietta sought to use it against Benedix.

The outcome was that each company successfully bid for the other. A third company – a 'white knight' – had to come in to unravel the mess. "It was seen as a big embarrassment, a net disaster all round," Gordon said.

Corporate lawyers in the UK are finding it difficult to predict the implications of Marstons' move. David Barnes, the corporate partner leading Linklaters' four-strong team, would not comment on the deal but said the defence had "given rise to some interesting issues".

The Marstons/Wolverhampton deal is not the first time Linklaters has been associated with a Pacman defence.

In 1989, partner Donald Williams headed a team advising Plessey in its unsuccessful attempt to stave off a bid by GEC. Plessey contemplated but did not use the defence.

Herbert Smith corporate finance partner Anthony Macaulay predicts "a lot of headaches ahead" for the lawyers involved.