Mongolia is expected to appoint banks by next week to manage an IPO worth up to USD5 billion for the world”s largest untapped coking coal deposit, sources with knowledge of the matter have told Reuters. More than 150 bankers from a dozen Wall Street, European and Asia-Pacific investment banks made pitches to the Mongolian government over the past few days to win the coveted underwriting mandate for the Tavantolgoi coal mine.

“Ten or 12 government officials were there. They listened and asked good questions, which isn”t always what you get with a government pitch,” said one banker who attended. Investment bankers who took part in the pitching process said the size of the offering could range from USD1.5 billion to USD5 billion, depending on timing. They declined to be named because they were not authorized to talk to the media.

Bankers completed their pitches in Ulaanbaatar on Tuesday and while a decision is expected by next week, sources said the timing could change. Listings on both the London and Hong Kong stock exchanges were being discussed, they added. Banks who flew representatives in included Morgan Stanley , Macquarie Group Ltd , Citigroup Inc , JP Morgan Chase & Co , Deutsche Bank AG , Credit Suisse Group AG and UBS AG , the sources said. The banks declined to comment.

At up to USD5 billion, the deal is not only fairly big in terms of fees, but also has a lot of prestige riding on it. It would be the largest such offering to come from a hot frontier market where similar deals are expected to follow.

Stories of bankers fighting in a bar in Ulaanbaatar made the rounds in Hong Kong in the days prior to the formal pitching sessions. Another hot topic amongst bankers involved concerned Morgan Stanley analyst Battushig Batbold, son of Mongolia”s prime minister. Batbold is a metals and mining analyst for Morgan Stanley in London, according to his LinkedIn profile.