Citigroup Inc banker David Wormsley, testifying in a civil fraud trial pitting the word of Terra Firma private equity chief Guy Hands against his, said on Monday he was "always truthful and honest as I could be" with Hands.

Wormsley wrote an email urging a colleague to show "big love" to Terra Firma, the jury heard in New York, where the trial featuring billions of dollars, storied music company EMI, the risks of the credit boom and high-profile lawyers began its second week.

The banker, called by Hands' lawyer, David Boies, took the witness stand for about 20 minutes near the end of Monday's proceeding in U.S. District Court to begin telling his side of the story in the dispute with Hands, 51.

The outspoken Terra Firma boss testified last week and Monday that Wormsley, 50, had misled him and lied to him about a rival bid for EMI from Cerberus Capital Management LP. As it turned out, there was no rival bid and Terra Firma believes it was pressured into overpaying.

Citigroup had ties with with all three parties.

Boies displayed a number of emails by Wormsley to try and establish with the nine jurors that there was good reason for Hands to trust one time friend Wormsley and believe him about Cerberus.

Asked by Boies to list the ways in which he worked to show Hands he was trustworthy, Wormsley said: "Principally, my general demeanor toward him. I would always be as truthful and honest as I could be."

The stakes are high in the contest of credibility over the European buyout house's decision to pay 4 billion pounds ($6.4 billion) for EMI in May 2007. The label, known for such star musicians as The Beatles, Pink Floyd, Nat King Cole and scores of others, is struggling under the weight of its debt.

The deal has come to reflect some of the worst aspects of the credit boom, when companies were loaded with debt.

If Terra Firma loses at trial, it could be forced to hand over EMI to creditor bank Citigroup, which provided 2.6 billion pounds ($4 billion) in loans for the acquisition.

The bank's reputation for facilitating such deals could suffer if the jury decides Hands was defrauded.

The two Englishmen were friends, attending dinner parties, going to the opera and on holiday with their wives. They kept up a business and social relationship after the EMI deal, but Hands sued in December 2009.

Citigroup argues he filed the lawsuit after realizing he made a bad business deal. In a tense cross-examination of Hands, Citigroup lawyer Ted Wells repeatedly tried to highlight potential inconsistencies in emails, documents and statements by Hands in and out of court.

"Did you lie to the jury?" Wells asked Hands at one point. Hands said he did not.

A November 2006 Wormsley email shown to the jury by Terra Firma lawyers said: "For reasons I won't go into, we have to show 'big love' to Terra Firma and it would be very helpful if you had an hour to work with the Terra Firma team." The email was addressed to then-colleague Julian Mylcreest.

Hands testified last week that, in the days before the May 21 deadline for bids, Wormsley told him in phone conversations that Cerberus was ready to bid 262 pence per share for EMI.

Hands said Terra Firma "scrambled" over a weekend to obtain financing to offer 265 pence per share. He said that, if the firm had known the Cerberus bid was nonexistent, it would have negotiated a lower price for EMI, a company he had coveted for about 16 years.

The case is Terra Firma et al v Citigroup et al, U.S. District Court for the Southern District of New York, No. 09-10459.