Shares in British Petroleum took a roller-coaster ride yesterday, as enthusiasts over the company's planned merger with Amoco Corp battled against determined selling from US arbitrage traders. By the close, the stock had slipped just a single penny to 794p in massive volume of around 73 million shares.

The stock had earlier posted strong gains, as investors continued to applaud the mega-merger announced on Tuesday which will create a giant company with a market value of $110 billion.

With a stream of positive comments from analysts fuelling demand, BP stock reached an intraday peak of 823p.

However, in a similar pattern to Tuesday's dealings, the advance of BP shares was abruptly halted as US arbitrage traders returned to sell the stock and buy Amoco shares.

Dealers said the arbitrageurs were exploiting the differences between the two share prices as a method of making instant profits or as a cheap way of gaining exposure to the deal.