UPDATE 1-Qatar plans 2nd limit on bank loans to fight inflation

(Adds analyst comment)

DUBAI, Feb 3 (Reuters) - Qatar plans next week to raise for the second time in two months the portion of deposits its commercial banks cannot lend in a bid to control inflation, the highest in the Gulf Arab region.

Qatar's central bank will increase the reserve requirement by 50 basis points to 3.75 percent, starting Feb. 15, said a central bank official on Sunday. The official declined to be identified.

Qatar raised its reserve requirement for the first time this decade on Dec. 12, by 50 basis points to 3.25 percent. There are 100 basis points in a percentage point.

The world's largest producer of liquefied natural gas, where inflation in September ran at a near record 13.7 percent, last week lowered its deposit facility rate by 50 basis points to match a cut in the United States. It kept its lending rates unchanged.

"It's a way to try to tighten monetary policy without lifting rates," said Simon Williams, Middle East economist at HSBC Holdings Plc in Dubai.

"It's a positive step, but it's difficult to gauge the impact on liquidity growth when you look at how quickly credit has been growing, and how entrenched inflationary pressures already are," Williams said.

Like other Gulf states -- bar Kuwait, Qatar pegs its currency to the U.S. dollar and tends to track U.S. interest rates to maintain the relative value of its riyal.

"It is due on Feb. 15," the central bank official said of the planned change. "We are now in a period of calculating the reserves for each bank according to their deposits, which we will know by Feb. 12 and then we will apply 3.75 percent."

(Editing by Jacqueline Wong)