* Egypt's Ezz Steel, Domty tumble after quarterly earnings

* DAMAC's pull-back drags down Dubai

* But index holds technical support

* Saudi Kayan falls despite Q2 earnings beat

* Qatari banks flat to lower after earnings

By Andrew Torchia

DUBAI, July 18 (Reuters) - Middle East stock markets fell on Tuesday as a tumble by real estate developer DAMAC caused Dubai to break a seven-session rising streak and weak corporate earnings helped to pull down Egypt's bourse.

The Egyptian blue chip index, which had closed at a record high on Monday, sank 1.7 percent in rising turnover - a negative technical sign. The broader EGX100 dropped 1.6 percent.

Ezz Steel plunged 10 percent after it reported a quarterly consolidated net loss after tax and minority interests of 521 million Egyptian pounds ($29.2 million), versus a loss of 137 million pounds a year ago.

The company said it had suffered from a very low rate of capacity utilisation because of a working capital shortage after the devaluation of the Egyptian pound; it expects to cover the working capital gap gradually in coming quarters.

Arabian Food Industries (Domty) slid 5.6 percent after reporting a second-quarter net profit of 12 million pounds, below some analysts' estimates.

Large-cap Orascom Telecom Media slipped 4.2 percent as its subsidiary Beltone Financial lost 3.6 percent.

In Dubai, the index dropped 0.7 percent to 3,578 points after rising for seven straight sessions through Monday, but it held technical support at 3,573 points, the April peak. DAMAC, which had led the rally, fell back 9.0 percent in heavy profit-taking.

The Saudi index slipped 0.5 percent. Saudi Kayan rose in early trade but closed 2.1 percent lower after reporting its second-quarter net profit climbed to 242 million riyals ($64.5 million) from 97.3 million riyals a year ago; analysts had on average predicted 212 million riyals.

Qassim Cement fell 0.4 percent after it reported a quarterly profit of 53.2 million riyals versus 113.9 million riyals; analysts had on average expected 66 million riyals.

But National Co for Glass Industries jumped its 10 percent daily limit after reporting a 224 percent leap in quarterly net profit, although operating profit actually fell sharply.

Jouf Cement gained 4.8 percent after shareholders approved a 10 percent capital increase via an issue of bonus shares, to be paid for with the company's retained earnings.

Qatar's index slipped 0.5 percent as Masraf Al Rayan , the second-largest bank by market value, dropped 1.4 percent.

It reported flat quarterly net profit, in line with analysts' forecasts, suggesting the impact of Qatar's diplomatic crisis has so far been minor. Customer deposits were 61.21 billion riyals ($16.8 billion) at the end of June, up 5.9 percent from a year earlier but down 3 percent from the previous quarter.