NEW YORK (Reuters) - Boeing Co reported profit dipped in the fourth quarter from a year earlier, and said its 2013 forecast "assumes no significant financial impact" from the grounding of its 787 Dreamliner passenger jet by regulators.

Earnings at the aerospace and defense company fell to $1.28 a share from $1.32 a year ago, excluding a special tax gain, it said on Wednesday, but results beat estimates of $1.19 a share. Revenue for the quarter rose 14 percent to $22.3 billion.

Aviation safety agencies in the United States and Japan are investigating what caused lithium-ion batteries to burn on two 787 jets earlier this month, prompting regulators to ground the planes worldwide.

Boeing said it is continuing to build the Dreamliner, but has halted deliveries, and analysts have raised concerns about the cost of the grounding and fixing the battery problem on about 125 jets that Boeing has built so far.

(Reporting by Alwyn Scott; Editing by Jeffrey Benkoe)