BANK of Ireland's £600 million purchase of the building society Bristol & West, is being considered by Britain's director general of Fair Trading.

The director general said in a statement that he was considering whether it qualified for investigation under the merger provisions of the Fair Trading Act.

A spokesman for Bank of Ireland said he understood the matter was just routine. Under British law any transaction of businesses with assets of more than £70 million is considered by the Office of Fair Trade.

The spokesman said the bank was confident the deal would go ahead. He said the deal was subject to several complex procedures and it would be next spring before it neared completion.

Bristol and West is the ninth largest building society in Britain and its shareholders will have to approve the takeover, as will an extraordinary general meeting of Bank of Ireland shareholders. "It is a slow and tedious the spokesman said, but added that the time frame was still shorter than most building society conversions.

The £600 million price will involve cash payments of about £500 million to Bristol & West members and preference shares in the new Bristol & West plc to the value of under £100 million.

If it goes through, the deal will enhance Bank of Ireland's total assets by around 40 per cent. Analysts say the acquisition will enhance the bank's earnings, adding about 10 per cent to annual earnings in 1998-1999.

Bristol & West has nearly 160 branches in the south west of England, mortgage assets of £7 billion and a deposit book of £6 billion.

Bank of Ireland already has a presence in Britain, with 27 branches. It has been in that market for 25 years.