* Agricultural damages now estimated at 705 million euros
* Industry lobby says quakes to lower national growth rate
* Latest aftershock hits coast near Ravenna (Releads with agricultural lobby estimates)
ROME, June 6 (Reuters) - Recent earthquakes in northern Italy have severely damaged some 2,000 farms and inflicted losses amounting to 705 million euros, agricultural lobby group Coldiretti said on Wednesday, lifting previous damage estimates by over 200 million euros.
The revised estimate came as the head of Italy's main business association said the earthquakes would halt output in many local factories for up to six months and could crimp national gross domestic product.
Earthquakes hit the area around Modena in the prosperous region of Emilia Romagna last month, killing 26 people, leaving more than 10,000 homeless, and damaging or destroying thousands of buildings including farms, factories and historic churches and castles.
Coldiretti said damage of about 400 million euros had been caused to farm buildings and another 70 million euros would be needed to secure damaged irrigation installations.
In addition, 220 million euros worth of damage had been done to production of Parmigiano Reggiano and Grana Padano, the two main varieties of parmesan cheese, and another 15 million euros of damage to production of Modena balsamic vinegar.
Coldiretti had previously estimated damage to the agricultural sector would total around 500 million euros.
Confindustria President Giorgio Squinzi said the two quakes and the almost uninterrupted series of smaller aftershocks that have rattled the area since would halt production in many factories by between four and six months.
"The area generates around 1 percent of GDP, so we risk losing a few fractions of a point of GDP just from the earthquakes," he told reporters at the margins of a conference in Rome.
In the latest in a series of aftershocks, a magnitude 4.5 tremor struck off the coast of the city of Ravenna early on Wednesday without causing any damage.
But with the summer holiday season approaching, the shock raised fears of a negative impact on tourism revenues. (Reporting By Antonella Cinelli; Editing by Mark Heinrich)