Feb 11 (Reuters) - Australian power producer AGL Energy AGL.AX narrowed its full-year earnings forecast on Wednesday, citing higher consumer margin and lower costs, while reporting a 6.4% fall in its first-half underlying profit.

AGL, also the top corporate carbon emitter in Australia,

narrowed its full-year forecast range for underlying net profit after tax to between A$580 million and A$680 million ($410.23 million and $480.96 million), compared to its previous range of between A$500 million and A$700 million.

It also reported first-half underlying profit of A$353 million ($249.68 million), below the A$377 million reported last year, but beating the Visible Alpha consensus estimates of A$307.4 million.

($1 = 1.4138 Australian dollars)

(Reporting by Sherin Sunny and Shivangi Lahiri in Bengaluru; Editing by Vijay Kishore)

((Shivangi.Lahiri@thomsonreuters.com;))