Mexico sold Banamex for $3.21bn in 1991; Citigroup paid $12.5bn for it a decade later

Banamex, founded in 1884, was nationalised in 1982 with more than 50 other Mexican banks. On 26 August 1991 the government sold the controlling interest to a group of about 800 investors led by Roberto Hernández's brokerage Accival for about $3.21 billion, or 2.6 times book value.

Hernández outbid a consortium of industrial families by 12% for 50.7% of the shares, with another 20% planned for managers and clients. The sale was part of a programme that returned all 18 commercial banks to private hands.

In 2001 Citigroup acquired Grupo Financiero Banamex-Accival for $12.5 billion, then the largest US-Mexico corporate merger, integrating more than 1,400 branches and 4,200 ATMs. The bank had remained one of Mexico's strongest through the 1994 peso crisis.

Sold for $3.21bn (2.6x book) in 1991; Citigroup paid $12.5bn in 2001, the largest US-Mexico merger to date

Auctioning control to the highest bidder at 2.6 times book value forced a market price test instead of a political allocation.

A banking-focused buyer with a top brokerage kept management expertise inside the bank.

Selling the banks quickly, in one programme, avoided the drift that weakens partial privatisations.

Selling a nationalised bank to the highest bidder at a fair multiple beat keeping it in state hands: the 1991 auction returned Banamex to private capital, and a decade later Citi paid $12.5bn.

Banamex operated under private ownership through Mexico's 1994-95 crisis and was acquired by Citigroup in 2001 for $12.5 billion, the largest US-Mexico merger to that date. The sale became the benchmark of Mexico's bank reprivatisation programme and is still cited as one of its clear successes.