According to a new study by Moody's Investors Service, at least two PE-backed U.S. companies -- Caesars Entertainment Corp. and a unit of Energy Future Holdings Corp. -- have benefited from strong investor demand for new secured bond offerings as they refinanced maturing bank debt.

Despite shaky ratings on the issuer, "Investors appear to have an appetite for the higher-ranked senior secured bonds of these companies as they search for yield amid today's low interest rates," Moody's analyst Suzanne Wingo wrote in a Tuesday, Feb. 14, report entitled "Low-Rated Private Equity-Owned Companies Face a Steep Maturity Wall From 2012-2014."

Moody's said $62 billion in debt will mature between 2012 to 2016 at 15 PE-owned U.S. companies with corporate ratings at B3 and below. Half of that debt will mature by 2014. And about half of the companies were among the largest leveraged buyouts between 2006 to 2008.

Last week, Las Vegas casino operator Caesars, owned by TPG Capital and Apollo Global Management LLC, issued $1.25 billion in 8.5% first-lien secured notes to help pay down portions of maturing debt. Moody's rated Caesars' debt at Caa2.

EFIH Finance Inc., a subsidiary of Texas utility Energy Future, the former TXU Corp., recently doubled the size of a $400 million offering of senior secured second-lien notes to $800 million. Proceeds from the offering, which priced at the tight end of price talks at 11.75%, will be used to pay back loans the utility took out from its subsidiaries.

Realogy Corp., a residential real estate broker owned by Apollo, recently raised $918 million of new high yield-bonds. The company said it would use the proceeds to prepay $762 million of bank debt coming due in October 2013 and $156 million of borrowings that mature in 2016.

Univision Communications Inc. priced $600 million in 6.875% secured notes at the end of January to help refinance debt due in 2014. The company, owned by Madison Dearborn Partners LLC, Providence Equity Partners Inc., TPG Capital, Thomas H. Lee Partners LP and Univision chairman Haim Saban, has a B3-stable rating from Moody's.

"There seems to be a bit more liquidity right now among bond buyers than in the syndicated loan market," said Richard Farley, a partner at Paul Hastings LLP.

Senior secured bonds are backed by collateral and have a higher likelihood of repayment in case of default than unsecured bonds, the Moody's report said. "Collateral may not lead to a high recovery, however, if there is little debt cushion provided by unsecured or subordinated notes in the capital structure," it said.

While some new investors may be looking to the bond market for higher yields, Farley said most investors in these types of refinancings are recycled, meaning that investors in old bonds typically make up a majority of the investors of a new bond.

However, Farley said, issuers should keep in mind that it may be more difficult to get consent on future acquisitions because of some terms on bond refinancings, especially ones with first-lien debt that is not pre-payable.