Unite saw pre-tax losses widen to £29.4m ($48.1m) for the six months to June 30, compared with a £11.5m deficit a year earlier.
However, the student accommodation developer said it was looking to acquire new sites in London, having created a separate £194m joint venture to develop its 2010 pipeline this month.
The loss reflected a £23m writedown in the value of the investment and development portfolio, as well as restructuring costs.
Unite said that sales and rental growth continued to be strong. Like-for-like rental growth is anticipated to be between 10 per cent and 11 per cent for the next academic year.
Recurring profit was £3.5m, from a loss last year of £2.9m. Net asset value per share dropped 12 per cent to 286p, from 325p at December 31. The group is on track to exceed its 2009 asset disposal target of £150m.
The shares closed up 11¼p at 209¼p.