LIKE every other business activity nowadays (except bankruptcy-advisory work) merging and acquiring companies (M&A) is in a deep slump. Last week BHP Billiton, a mining giant, withdrew from its planned hostile acquisition of Rio Tinto. This is part of a trend of corporate grooms abandoning their would-be wives at the altar. According to Thomson Reuters, that takes the total value of cancelled mergers so far in this quarter to $322 billion, a two-year high and almost as much as the value of completed mergers in this quarter ($362 billion).

Another study, by UBS, found that one-third of the deals announced in America this year have been terminated before consummation. And the number of proposals is down overall this year. Worldwide, the value of mergers and acquisitions completed so far in 2008 is $2.8 trillion, down by 27% from the same time last year.

Shares in Rio Tinto plunged by 37% after BHP withdrew its offer, which suggests it was a wise decision to pay whatever break-up fees it will incur. The general plunge in share prices will cause many bidders to rethink offers that seemed reasonably priced only a few months ago.

Although BHP had secured the necessary debt