Qatar's economic growth rebounded to 6.2 per cent on an annual basis in January-March after a slowdown in the final quarter of 2013 as a double-digit surge in construction activity  helped offset a decline in hydrocarbons, data showed on Monday.Overall gross domestic product growth slowed to a downwardly revised 5.5 per cent in the previous quarter due to a sharp fall in the hydrocarbon sector, which accounts for more than half the $202 billion economy. Other sectors continued to expand rapidly."The high growth in the first quarter of 2014 is the result of a double-digit rise seen mainly in construction, trading, hospitality and financial sectors coupled with over 9.2 per cent jump in the country's population," the Qatar Statistics Authority said.An expansion of Qatar's gas facilities  helped fuel breakneck GDP growth averaging 17 per cent a year between 2006 and 2011, but the economy slowed to 6.2 per cent in 2012 as the gas expansion ended and works on a raft of mega projects were slow to start. Growth picked up slightly to 6.5 per cent last year.On a quarterly basis, the Opec member's economic output growth quickened to 2.3 per cent in the first quarter from a meagre 0.6 per cent in October-December, the data showed.Activity in Qatar's construction sector soared 19.6 per cent from a year ago in January-March, faster than a 13.6 per cent rise in the whole last year, and 12.9 per cent from the previous quarter, according to the preliminary estimates.On the contrary, the decline in the oil and gas sector deepened marginally to 1.2 per cent year-on-year from 1.1 per cent in the fourth quarter. Its output rose 1.8 per cent quarter-on-quarter, however, after a 2.8 per cent slump in October-December."The receding crude oil production and the flat full capacity gas production primarily explain the decline in this sector," the statistics authority said.Non-oil growth is likely to stay robust this year as the world's top liquefied natural gas exporter plans to spend some $210 billion on infrastructure, including roads and stadiums, ahead of the 2022 World Cup soccer tournament, keeping the overall rate above 6 per cent.Last week, Doha raised its 2014 GDP growth forecast sharply to 6.3 per cent from the previous 4.6 per cent, well above growth rates of the fellow Gulf Arab oil exporters, citing robust domestic demand.A Reuters poll in April was slightly less optimistic, forecasting a 6.1 per cent expansion this year and 6 per cent in 2015.