* Fraport, GIP, Brookfield, Allianz put in tentative offers - sources
* Hochtief could fetch as much as 1.2 billion euros - sources
* Hochtief shake-up driven by new owner ACS
By Arno Schuetze
FRANKFURT, April 15 (Reuters) - German builder Hochtief , controlled by Spain's ACS, has received bids for its airport unit, two people with knowledge of the matter said.
Hochtief, which halted the sale of its six airport stakes early last year when it was unable to fetch a price of 1.5 billion euros ($2 billion), is trying again to sell its stakes in airports in Duesseldorf, Hamburg, Budapest, Sydney and Tirana. It has for now given up on looking for a buyer for Athens airport.
A source representing a potential buyer of the assets has said Hochtief could now fetch as much as 1.2 billion euros in the sale, which Deutsche Bank is organising. Deutsche Bank declined to comment on the matter.
Fraport, the operator of Frankfurt airport, Global Infrastructure Partners Ltd (GIP), which owns London's City and Gatwick airports, Canada's Brookfield Asset Management , and insurer Allianz have all put in offers, the sources said.
One additional bidder has put in a tentative offer for only the German operations up for sale, one of the sources said.
Hochtief, Fraport and Allianz declined to comment, while GIP and Brookfield were not immediately available for comment.
Hochtief Chief Executive Marcelino Fernandez Verdes, who took the top job in November, is leading a drive to shed airports and real estate development businesses to cut the company's debt while making it a leading global infrastructure provider.
Fraport said last month it was considering buying more stakes in airports, citing Brazil among other places.
Allianz has said in the past that investments in airports and highways could fit into its alternative investment strategy, but that it would generally look for an industry partner to actually run the acquired assets.
French construction group Vinci, China's HNA Group, parent of Hainan Airlines, and a consortium of airport operator Fraport and Deutsche Bank fund RREEF were among the bidders last year before the sale was suspended.
Vinci late last year sealed a deal to buy Portugal's airports operator ANA for 3.08 billion euros.
Verdes was made CEO of the construction and industrial services provider in November to review the company's strategy, in a push by indebted majority owner ACS to make the 2011 takeover of Hochtief pay off.