Helicopter makers AgustaWestland, Airbus Helicopters and Sikorsky Aircraft have submitted bids on a big-ticket Polish chopper deal to replace Soviet-era military equipment, Poland's defence ministry said Tuesday.

The firms are vying for a contract worth an estimated 2.5 billion euros ($3 billion) to assemble 70 multi-purpose helicopters for Poland's army.

Whoever wins will ink the contract in the second half of 2015, the defence ministry said in a statement.

British-Italian group AgustaWestland and US manufacturer Sikorsky both already have helicopter plants in Poland, while Europe's Airbus -- formerly Eurocopter -- signed a deal last year aimed at setting up production there.

The helicopter tender is seen as a significant step in Poland's drive to replace 250 Soviet-era helicopters, part of a planned overhaul of its military equipment.

The overhaul will include acquiring a national missile shield, armoured personnel carriers, submarines and drones. Warsaw plans to spend around 140 billion zloty (33 billion euros, $40 billion) on the upgrade over 10 years.

Russia's aggression in the region has been central to Poland's military revamp, which the ex-Soviet satellite has sped up since the crisis erupted in neighbouring Ukraine.

Legislation in force since 2001 has fixed Polish defence spending at 1.95 percent of gross domestic product, but President Bronislaw Komorowski recently proposed raising it to two percent.

The central European powerhouse of 38 million people joined NATO in 1999, a decade after shedding communism. It became a member of the European Union in 2004.