(Corrects to say net profit in last year period)
VIENNA, Dec 19 (Reuters) - Austrian property group Immofinanz slid to a first-half net loss of 154.4 million euros ($161 million) from a 133.2 million profit a year ago, partly due to falling rental income and property valuations in its Russian portfolio, which it is trying to sell or spin off.
Despite a 28 percent increase in its operating income to 87.6 million euros, Immofinanz said on Monday its net result was also hit by a 106 million euro write-down of its 26 percent stake in rival CA Immo.
Earlier on Monday Immofinanz said a delay to the closing of a sale or a spin-off of its Russian portfolio - a precondition to the planned merger with CA Immo - would push a shareholder vote on the merger back into 2018. ($1 = 0.9578 euros) (Reporting by Shadia Nasralla; Editing by Adrian Croft)