Allianz-Snam win bid for 49 pct of OMV's Gas Connect Austria

* Allianz (Hanover: ALVN.HA - news) , Snam (Amsterdam: QE6.AS - news) to pay 601 mln eur for GCA stake

* Snam expanding control over European gas grids

* OMV (EUREX: 430021.EX - news) in need of cash as oil price bites (Adds detail on GCA dividend, Snam strategy)

MILAN/FRANKFURT/VIENNA, Sept 22 (Reuters) - Germany's Allianz and Italian gas grid company Snam said they will buy 49 percent of pipeline company Gas Connect Austria from energy group OMV for 601 million euros ($675 million), confirming an earlier Reuters report.

Investors like insurance companies such as Allianz are increasingly turning to infrastructure projects offering regulated returns to help them secure yields and offset the impact of low interest rates.

Thursday's deal strengthens state-controlled Snam's hand in its efforts to become a prime mover in the integration of Europe's gas grids.

OMV is selling non-core assets to generate cash while restructuring its gas business after low oil prices hit profits and shrinking refining margins provide less of a buffer to lower exploration and production profits.

Snam, Europe's biggest gas pipeline operator, has a strategic alliance with Belgium's Fluxys and also controls French grid TIGF and Austrian pipeline TAG (Other OTC: TAGOF - news) . It also recently bought a 20 percent stake in the Trans Adriatic Pipeline that will bring Azeri gas into Europe.

The price for Thursday's deal is at the upper limit of a range sources had indicated for the stake, which Australia's Macquarie together with Czech energy group EPH had also been interested in.

The effect of the cash deal will be backdated to Jan. 1 2016, but OMV is entitled to keep GCA's dividend for 2015, OMV said, with a spokesman adding this would mean an additional 40 million-euro windfall for OMV.

Allianz and Snam will hold 60 percent and 40 percent respectively of the acquisition vehicle.

GCA, which had revenues of 248 million euros in 2014, operates pipelines stretching across 900 kilometres (560 miles) in central Europe, supplying Austria, Germany, France, Slovenia, Croatia, and Hungary. It also deals with gas marketing. ($1 = 0.8909 euros) (Reporting by Stephen Jewkes, Arno Schuetze, Shadia Nasralla; Editing by Agnieszka Flak/Ruth Pitchford)