(Adds data, ministry and economist quotes)
BUENOS AIRES, March 30 (Reuters) - Argentina's economy expanded 2.1 percent last year, with growth slowing sharply in the last quarter of the year, preliminary data from the INDEC statistics agency showed on Wednesday.
The 2015 growth figure came in well above private economist expectations, and was driven by solid expansions in the agricultural, construction and public sectors.
A breakdown of the data showed Latin America's third largest grew 3.9 percent in the second quarter of last year, after shrinking 0.3 percent in the January to March period. But growth decelerated to 3.5 and 0.9 percent in the following quarters.
The data "shows a temporary recovery of GDP in the first half of the year, followed by a strong fall in the second half of the year," the Finance Ministry said in a statement.
The ministry put the blame for the slowdown on the overvalued currency last year and obstacles to business imposed by the previous, leftist government which handed power over to free-marketer Mauricio Macri in December.
Macri won last year's election on promises of rebooting the economy and has already lifted capital controls, spurred a devaluation of the peso, and cut export taxes.
Yet he has inherited other major challenges such as double-digit inflation and a yawning fiscal deficit that will take longer to tackle. The external context, with a recession in main trade partner Brazil and an overall slowdown in emerging markets, does not provide much consolation.
INDEC also said on Wednesday it was revising its entire series for economic activity from 2004 to 2015 and would publish its results in June. Much data published by the former government broadly is seen as lacking credibility.
"We expect a downward revision on real gross domestic product and potentially on nominal GDP, as private estimates show both were overestimated," said Alejo Costa, chief strategist at local brokerage Puente.
Argentina's economy grew 5.2 percent on average per year between 2004 and 2015, according to the official data currently available. Revised data for the period will be published alongside the GDP figure for the first quarter of 2016 on June 29, INDEC said. (Reporting by Sarah Marsh; Editing by Phil Berlowitz, Bernard Orr)