* Q1 EBITDA 1.22 billion eur vs 1.25 billion in Reuters poll
* Says energy reforms wipe 76 million euros from Q1 EBITDA
* Weak Latin American currencies also weigh on profits (Adds details and background)
MADRID, May 6 (Reuters) - Spanish gas and electricity firm Gas Natural Fenosa on Tuesday posted a 4.7 percent decline in first-quarter core profit, hit by regulation changes on its home turf and the impact of lower currencies in its Latin American markets.
A government overhaul of the energy sector has hit Spanish utilities such as Gas Natural, which said a new power generation tax and cuts to renewable energy subsidies wiped 76 million euros ($105 million) from first-quarter core profit.
Earnings before interest, taxes, depreciation and amortisation (EBITDA) totaled 1.22 billion euros in the quarter, slightly below the average 1.25 billion euros forecast in a Reuters poll of six analysts.
Barcelona-based Gas Natural, which generates about 40 percent of EBITDA abroad, said the depreciation of Latin American currencies against the euro, mainly the Brazilian real and the Colombian peso, hit EBITDA by 44 million euros more than in the first quarter of 2013.
EBITDA did not include contribution from various affiliates, including Union Fenosa Gas and Puerto Rican Ecoelectrica, which were deconsolidated as of January 1 to comply with international accounting norms.
Shares in Gas Natural, which have gained 12 percent so far this year, were down 0.26 percent at 20.795 euros at the open, in line with trading on Spain's blue chip index.
The company, with first-quarter net profit of 402 million euros, said it cut net financial debt by 8.2 percent to 14.17 billion euros at March 31 from a year ago, giving it a net debt/EBITDA ratio of 3.0 times. ($1 = 0.7205 Euros) (Reporting by Tracy Rucinski; Editing by Fiona Ortiz)