* Q1 rental income rises 14.2 pct to 162.3 mln euros
* Profit from operations up 22.6 pct to 121.7 mln euros
* Expects stable growth to continue in line with "high" Q1 (Adds details and background)
VIENNA, Sept 25 (Reuters) - Austrian property group Immofinanz lifted first-quarter profit from operations by 22.6 percent to 121.7 million euros ($157.2 million), boosted by higher rental income from an acquisition, it said on Tuesday.
Net profit fell by around two-thirds to 9.2 million due to the non-cash impact of foreign exchange translations and valuation of derivatives, it said. Excluding these, net profit fell nearly 19 percent but cash flow rose by two thirds.
"For the remainder of this financial year, we expect to continue our stable growth in line with the high first quarter," Chief Executive Eduard Zehetner said.
Immofinanz in August forecast sharply higher profit this year thanks to the takeover of a shopping centre in Russia and faster turnaround times for selling assets.
Zehetner said at the time profit from operations should rise to around 600 million euros in the year to April 2013 from 479 million in 2011/12.
Immofinanz has assets in Austria, eastern Europe, Germany and Russia. More than half its assets are in eastern Europe, where it is contemplating a market listing.
The company on Monday unveiled plans for a share buyback worth up to 50 million euros that will use up 5 cents of its planned 20 cent per share dividend for its 2012/13 fiscal year.
"A large number of investors (has) welcomed this unusually attractive dividend return, but would also like to see - as an alternative or additional step - a share buyback, as long as the discount to the NAV is as high as it is right now," Zehetner had said in a statement.
$1 = 0.7743 euros Reporting by Michael Shields; Editing by David Cowell and Louise Heavens