* Impairment charge increased to 1.3 bln eur from 810 mln
* Most of 247 million euro profit due to tax credit
* Says on track to pay back 7.5 bln eur next year (Adds analyst quote, details)
DUBLIN, July 25 (Reuters) - Irish state-run property giant the National Asset Management Agency (NAMA) made a profit of 247 million euros ($299 million) in 2011 as a large tax credit helped make up for a bigger-than-expected impairment charge.
Created to purge Irish banks of their risky land and development loans, NAMA has said it expects to break even by the time it is wound down at the end of the decade, but is heavily dependent on a rebound in Irish property prices.
In its annual report released on Wednesday, the agency booked impairment charges of 1.27 billion euros for 2011, up 57 percent from an estimated impairment of 810 million in unaudited accounts released in April.
A tax credit of 235 million euros not specified in the unaudited accounts helped boost an 11 million pre-tax profit.
The agency made a loss of 1.18 billion in its first year of operation in 2010 after taking a 1.49 billion euro charge to cover potential losses from the loans it acquired.
"It's slightly disappointing, but NAMA is a very long term situation," said Owen Callan, a senior dealer at Danske Markets.
"What is key for them is the second half of this year and particularly next year when they start to sell off their Irish property assets."
Most of NAMA's sales so far have been in Britain, which has not experienced the collapse in property prices seen in Ireland since 2007.
Chief executive Brendan McDonagh said the agency was "well on track" to meet an interim target of paying off 7.5 billion euros of senior debt by the end of 2013.
The agency paid 31.8 billion euros for assets with a book value of 74 billion euros. ($1 = 0.8275 euros) (Reporting by Conor Humphries and Padraic Halpin; Editing by Elaine Hardcastle)