CARLTON has upped the ante in its bid to retain Zach Tuohy, offering the defender "a healthy three-year deal".

Tuohy is due to come out of contract at the end of next month and has attracted keen interest from several clubs, with North Melbourne reportedly offering him a four-year deal.

Carlton was initially understood to have offered Tuohy a new two-year contract, but club CEO Steven Trigg told SEN on Wednesday the Blues now have a three-year deal on the table.

"We'd like Zach to stay, he's got a very healthy three-year deal in front of him and like a bunch of players around the competition at the moment he's just weighing up his options, which is not unreasonable," Trigg said.

"We want him to stay at the footy club, he's been very durable and he's a very strong senior player.

"I know there are a couple of clubs having conversations with his management, but we'll see where that one lands – we'd like him to stay."

It is believed Tuohy's first preference is to continue his career at Ikon Park, where he has played 120 games since joining the Blues as an international rookie ahead of the 2010 season.

The 187cm defender enjoyed a career-best season in 2015 that saw him named on a back pocket in the AFL Coaches' Association team of the year and finish third in Carlton's best and fairest award.

The Irishman enjoyed another strong season this year, finishing seventh in the John Nicholls Medal count after averaging a career-high 20 possessions a game. 

Tuohy also finished third at Carlton for rebound 50s (91) and fifth for inside 50s (64), while he racked up a personal-best 35 possessions against Hawthorn in round 19 and starred with 25 disposals and three goals in the following round against St Kilda.

Tuohy was recruited from County Laois in Ireland's midlands region, and made his AFL debut against Port Adelaide in round 11, 2011.

He has not missed a game since the opening round of 2013, and his run of 90 consecutive games is the longest active streak at Carlton and fourth in the AFL behind Sam Gibson (108), Nathan Jones (97) and Dane Rampe (95).