The commitment deadline on $10 billion of pro-rata loans in a $45 billion financing package backing computer giant Dell’s purchase of data storage products maker EMC Corp has been extended due to a slow order book, a source close to the transaction said.

The Chinese New Year, which delayed approval of requests from foreign banks' home offices to participate in the financing, was the main reason for extending the original February 10 deadline, the source said.

Pro rata loans are primarily sold to banks, and Asian and European lenders are an important component.

"Asian banks -- Chinese and Taiwanese -- they have balance sheets and an ancillary connection with Dell and EMC," a banker following the transaction said, adding documentation delays are not uncommon at this point of the marketing process.

The pro-rata syndication is now not anticipated to close until at least February 15.

Sinking oil prices, an equity sell-off and increased dollar funding costs are making it more expensive for some banks to lend and were expected to make Dell’s pro-rata loans a tougher-than-expected sell.

“Am I worried? Of course, I’m worried," a banker close to the transaction told Thomson Reuters LPC after the loans launched to investors two weeks ago.

The loans are testing banks’ appetite for funded U.S. dollar assets before tapping the institutional loan and high-yield bond markets.

The sheer size of the pro-rata loans was expected to make the deal challenging. Dell is the second largest pro-rata financing to date behind a $13.9 billion pro-rata package from July 2015 that backed Canada Pension Plan Investment Board’s acquisition of Antares Capital from General Electric Capital Corp.

Industry concentration was also expected to bring challenges. The heavy issuance in the tech space last year could limit investor interest in the credit.

Dell’s $10 billion pro-rata loans include a $3.5 billion three-year term loan, a $3.5 billion five-year term loan and a $3 billion five-year revolving credit facility.

The loan package also includes an $8 billion seven-year Term Loan B that will be sold to institutional investors and $25 billion of high-yield bonds, both of which will come to the market before the acquisition is scheduled to close in August.

Bankers seeking to boost demand priced the revolving credit facility at 37.5 basis points undrawn and 200 basis points over Libor drawn, while the three-year term loan pays 200 basis points over Libor and the five-year pays 225 basis points over Libor.

“It’s priced to sell,” another banker said.

The JP Morgan-led loans launched to bank investors in New York on January 27.

Other underwriting banks are Barclays, Bank of America Merrill Lynch, Citigroup, Credit Suisse, Deutsche Bank, Goldman Sachs and RBC Capital Markets.

Even if the deal takes longer to sell, Dell’s strong enterprise-oriented business model, the credit quality of the name (expected corporate ratings Ba1/BB+, expected debt ratings Baa3/BBB), and a focus on paying down debt are seen encouraging banks to absorb the pro-rata loans.

(Reporting By Michelle Sierra; Editing by Lynn Adler)