UPDATE 1-Spain developers Q1 revs scarred by credit freeze

* Realia revenues fall 49 pct to 74.8 mln euros

* Data shows average home 32 pct cheaper than yr ago

* Reyal Urbis revenues down 22 pct to 147 mln

* Martinsa Fadesa swings net loss of 27 mln euros

* Metrovacesa revenues drop 39.1 percent to 121.9 mln (Adding earnings data for Martinsa Fadesa, Metrovacesa)

MADRID, May 13 (Reuters) - Spanish property developers reported sharp falls in first quarter earnings on Wednesday as home sales dried up in one of Europe's worst hit property markets.

Groups to report included Realia (RLIA.MC), Reyal Urbis (REYU.MC), Martinsa Fadesa (MFAD.MC) and Metrovacesa (MVC.MC)

House sales in Spain have fallen 34 percent in the year to March, and prices have declined faster than indicated by official statistics, showing a 6.8 percent fall in the first quarter.

Reyal Urbis said first quarter revenues fell 22 percent to 147 million euros ($200.6 million) though it swung into a profit of 22.5 million thanks to 74.5 million euros of tax breaks after making a loss last year.

Although rival Realia managed to lift pre-sale orders by 61 percent to 126 homes, it only did so after cutting the average price of the properties by 32 percent to 177,000 euros, Reuters calculations show. Margins in house sales fell to 1.4 percent compared to 16.4 percent a year earlier.

Revenues nearly halved to 78.4 million euros.

Realia, which is 50 percent owned by savings bank Caja Madrid and construction firm FCC (FCC.MC), said its net debt swelled to 2.34 billion euros at the end of March -- 12 percent higher than a year earlier.

It is currently negotiating with creditors to refinance its debt due this year -- 36 percent of the total.

Martinsa Fadesa, which entered in to administration last summer, reported a net loss of 27 million euros in the first quarter, while revenues rose 62 percent amid an property asset fire sale made to meet debt obligations.

The group reported negative gross margin of 7 million euros in the first quarter and a fall in earnings before interest, taxes, depreciation and amorization (EBITDA) of 26 million euros.

Spain's biggest property company, Metrovacesa, (MVC.MC), which specialises in renting commercial space, reported a 39.1 percent fall in revenues to 121.6 million euros while EBITDA dropped 89.6 percent to 12.2 million euros after a revaluation of asset worth.

Metrovacesa reported a net loss of 90.2 million euros compared to a net profit of 102.3 million euros a year earlier due to debt refinancing costs and provisions made against the reduced value of its stake in Gecina (GFCP.PA), the group said. (Reporting by Andres Gonzalez, Ben Harding and Paul Day; Editing by David Cowell)