* Economic activity rose 3.8 pct in Feb from year ago
* It fell in monthly terms for 2nd time in a row
SANTIAGO, April 5 (Reuters) - Chile's economic activity expanded 3.8 percent in February from the same month a year ago, it slowest pace in nearly a year and a half, constrained by fewer working days, the central bank said on Friday.
The IMACEC indicator of economic activity, considered a proxy for economic growth, also slipped 0.1 percent in February from January, after falling a downwardly revised 0.2 percent in January from December.
The IMACEC's growth from a year earlier fell short of the expected 4.9 percent rise in February, according to the median estimate of 16 analysts and economists polled by Reuters.
"The result was affected by the fewer days registered in the month, compared with February last year, which was a leap year," it added.
After economic activity surged a downwardly revised 6.5 percent in January versus a year ago, Finance Minister Felipe Larrain cautioned that export-dependent Chile was not going to maintain the same level of growth all year.
Earlier this week, Chile's central bank cut its 2013 inflation forecast on Tuesday but hiked its projection for growth in gross domestic product to a range of 4.5 percent to 5.5 percent, citing the robust expansion of domestic demand as a risk to the nation's economy.
Chile's economy grew 5.6 percent in 2012.
The central bank calculates its month-on-month IMACEC data in seasonally adjusted terms. A monthly gauge, the IMACEC measures more than 90 percent of the components comprising Chile's gross domestic product, which is published quarterly.