Shares of U.K. music company EMI Group Plc closed down 5.2% on Wednesday as concerns grew that its private equity buyer Terra Firma was having trouble securing financing for the deal.

Terra Firma and adviser Citigroup were haggling over the terms of the debt ahead of a Sunday deadline, people familiar with the situation said, because of deteriorating conditions in credit markets since the deal was announced in May.

Citigroup and Terra Firma declined comment. No-one at EMI could immediately be reached for comment.

Terra Firma agreed to buy EMI, home to Coldplay and Robbie Williams, for £2.4 billion ($5 billion) on May 21 but the music group's investors were slow to sell their shares, waiting instead to see whether rival Warner Music Group would make a counterbid.

New York-based Warner Music finally ruled itself out early last week and Terra Firma said on Friday that it had secured 26% of the stock.

It needs to have 90% of the stock by 1200 GMT on Sunday, July 29, under terms of the deal, and would require Citigroup to sign off on any extension.

The deal prices EMI shares at 265 pence. They closed at 247.75 pence on Wednesday. Trading volume was more than 54 million shares, more than twice the average daily volume of 25.4 million over the last 30 days.

Citigroup is advising EMI and arranging debt for the acquisition.

Despite market fears about lending conditions, buyout professionals not involved with the transaction said they would be surprised if Citigroup were to abandon Terra Firma because it would likely damage the U.S. bank's reputation.

Analysts also said they expected the deal to go through.

Turmoil has hit the credit market within the last six weeks and on Wednesday Chrysler Corp. became the latest victim, postponing $12 billion of loans associated with its leveraged buyout by Cerberus Capital.