UPDATE 1-Peru's central bank raises key rate to 5.5 percent

(Adds quote, context, background on inflation)

LIMA, April 10 (Reuters) - Peru's central bank said it raised its benchmark interest rate to 5.50 percent from 5.25 percent and increased deposit requirements for lenders on Thursday, in the latest effort to help curb inflation.

Economists polled by Reuters earlier this week said they thought the bank would hold the benchmark rate constant in order to avoid excessive appreciation of Peru's sol PEN=PE.

In a statement after its meeting, the central bank said it raised the minimum legal deposit rate on bank accounts to 8.5 percent from 8 percent, and the marginal deposit rate for bank accounts denominated in the Peruvian currency to 25 percent from 20 percent. The bank lifted the marginal deposit rate on foreign-currency bank accounts to 45 percent from 40 percent.

The bank said higher deposit requirements would be equivalent to a 50-basis-point interest-rate increase.

The new deposit rules will take effect next month.

"The aim of these monetary measures is to slow the growth of credit and to prevent price rises, stemming from food supply shocks, from having a lasting impact on inflation expectations," the statement said.

Peru's economy, one of the fastest growing in the world, expanded by some 9 percent last year, but inflationary pressures have started to pick up, especially for imported foodstuffs.

Consumer prices rose 1.04 percent in March, the highest jump in about four years.

The central bank's annual inflation target is 2 percent, plus or minus one percentage point. Last year, inflation was nearly 4 percent.

So far this year, the Finance Ministry has cut import tariffs, reduced gasoline taxes and trimmed government spending in an effort to curb rising consumer prices. It has said it expects inflation to be around 3 percent in 2008.

In March, the central bank said it was raising reserve requirements for banks to try to absorb a flood of dollars that has entered the country and caused Peru's currency to rally to levels unseen since 1998. The bank also increased requirements in January, when it last raised the interest rate, to 5.25 percent from 5.0 percent.

Central Bank President Julio Velarde has previously said he would rather raise reserve requirements than increase the interest rate. (Reporting by Teresa Cespedes; Writing by Dana Ford; Editing by Jan Paschal)