Dubai's largest bank, Emirates NBD (ENBD), has taken advantage of strong support from lenders to sign a $1.7 billion three-year loan, $450 million more than it had originally sought, banking sources said on Thursday.

Gulf banks are keen to raise funds as liquidity comes under pressure from lower oil prices and before possible increases in borrowing costs this year if the US Federal Reserve raises interest rates again.

Another of the emirate's banks, Commercial Bank of Dubai (CBD), is expected to sign a three-year loan of up to $500 million in the next few days to refinance existing debt, sources familiar with the matter told Reuters on Thursday.

ENBD's loan, arranged by Bank of America Merrill Lynch and Emirates NBD Capital, was initially planned to be for $1.25 billion but was increased after substantial oversubscription, the banking sources said. A total of 19 banks participated in the deal.

ENBD declined to comment.

Bankers put the pricing of the deal at either 145 basis points or 150 basis points over the London interbank offered rate (Libor) all-in, meaning that it is inclusive of margin and fees.

Some of the proceeds will be used to refinance an existing $800 million loan that matures in December. That deal was signed in December 2013 and priced at 140 basis points over Libor, according to Thomson Reuters LPC data.

Eight to 10 banks are providing the CBD loan, including Citigroup, National Bank of Abu Dhabi, Commerzbank and Standard Chartered, sources said.

Commerzbank is coordinating the loan, which will carry all-in pricing of 155 basis points over Libor, sources said.

Two of the sources said that CBD was looking for $500 million but might have to settle for $450 million.

CBD declined to comment.

The money is being raised to refinance a $450 million loan that matures in December, the sources added. That three-year facility was priced at 125 basis points over Libor, according to Thomson Reuters data.

Borrowing costs have risen in recent months as investors have priced regional debt higher because of concerns about the impact of lower oil prices on liquidity levels.-Reuters