LONDON, Dec 6 (Reuters) - Dealmaker Ian Hannam is suing

Randgold Resources for up to $18 million he says he is owed for

work on its acquisition by Canada's Barrick Gold ( GOLD ),

telling a London court on Friday that the gold miner reneged on

their agreement.

Hannam was formerly one of JPMorgan's top rainmakers and

nicknamed the "king of mining" for his record of brokering deals

in the resources sector, including the merger of BHP Billiton in

2001 and the 2012 merger of Glencore and Xstrata.

His reputation was, however, dented more than a decade ago

when he was fined 450,000 pounds (now roughly $574,000) for

improperly disclosing information, though his actions were not

found to lack integrity.

Hannam entered the witness box this week to give evidence

for his advisory boutique Hannam & Partners' case over an

agreement he says was reached shortly before Barrick's 2018

acquisition of Randgold, which says the lawsuit is baseless.

Hannam & Partners says it was promised a minimum of $10

million, with the figure to increase if the deal was worth more

than $10 billion.

Its lawyers say Hannam brokered discussions involving

Randgold's then CEO Mark Bristow and Barrick's then executive

chairman John Thornton, which led to the merger.

After Barrick and Randgold agreed a deal ultimately worth

some $18 billion, Hannam asked for $18 million but was rebuffed.

"The Barrick-Randgold merger has been hugely successful,"

Hannam & Partners' lawyer Matthew Hardwick said on the first day

of the trial on Wednesday, adding: "But for Ian Hannam's vision,

it would not have happened."

Randgold's lawyer George Spalton, however, said there was no

written evidence of the alleged agreement and that $18 million

was roughly what Randgold paid its financial advisors, Barclays

and Canadian Imperial Bank of Commerce.

Spalton played Hannam a voicemail left by Bristow, now

Barrick's CEO, shortly after Hannam & Partners sent an $18

million invoice, which Bristow said was "completely

unprofessional".

Spalton also referenced Hannam's 2012 fine for sending two

emails on a client's behalf, suggesting Hannam had a reputation

he "could not be trusted with confidential information" which

meant Barrick did not want him involved.

Hannam denied that, adding he had accepted his fine and been

permitted to open Hannam & Partners by Britain's Financial

Conduct Authority.

"I have apologised and I have taken my punishment," he said.

The trial is due to conclude next week with a ruling

expected at a later date.