Credit Suisse First Boston and IMI, the Italian investment bank, could win one of the biggest new issue mandates of the year after the decision by the Italian government to press ahead with the sale of a fifth tranche of shares in ENI, the oils and energy conglomerate, within the next year.

The two banks have together led the first four sales of ENI, which started in November 1995 with a $3.95bn privatisation. Subsequent sales in October 1996 ($5.9bn), July 1997 ($7.8bn) and June 1998 ($7.3bn), have raised an astonishing $25bn, making CSFB and IMI's relationship with the Italian treasury one of the most lucrative equity capital markets partnerships in recent years.