NATO-member Poland is in the market for 70 new military helicopters, more than double the number it first sought in March, Prime Minister Donald Tusk said Wednesday.

"We're determined to speed up and expand our helicopter plans with the immediate decision to buy 70 helicopters for the Polish army," the PAP news agency quoted Tusk as saying.

Delivery of the first choppers is expected by 2014, he said, describing the cost of the project as "gigantic", but declining to name a figure.

In March, Warsaw announced a tender to buy 26 multipurpose helicopters for its army worth an estimated 1.5-3.0 billion zlotys (360-720 million euros, $480-960 million).

The move is seen as a significant step in the Polish army's drive to replace 250 Soviet-era helicopters in the years to come.

A former communist state of 38.2 million, among the first to join NATO in 1999 and member of the European Union since 2004, Poland has two helicopter plants, run by British-Italian AgustaWestland and the US Sikorsky Aircraft respectively.

Polish media have tipped them as the odds-on favourites in the tender.

AgustaWestland in 2010 bought Polish helicopter producer PZL Swidnik, which makes the Sokol helicopters used in rescue operations, by firefighters and for transport, and above all by the army.

It sells its helicopters in Poland, the Czech Republic and South Korea.

AgustaWestland plans to start producing AW 109, AW 119 and AW 139 helicopters in Swidnik in southern Poland, alongside parts for the AW 101 model.

Sikorsky has started to produce a new version of the Black Hawk S70i for export in the PZL Mielec plant, also in southern Poland

Tusk was on Wednesday visiting a military exercise range in Drawsko, northwest Poland, where Polish forces are currently staging their largest annual military exercise, code-named Anakonda 12.

He also announced that Poland's failed attempt to build its first naval corvette-type vessel -- a decade-old project dubbed Gawron and mired in allegations of high-level corruption -- will be salvaged by completing the craft as a patrol boat.