James Franklin has called time on his international career with New Zealand to join Middlesex on a two-year contract.
The England and Wales Cricket Board is expected to allow the 34-year-old to play as a non-overseas player because of his Irish ancestry.
The all-rounder, who will continue to play for Wellington until the end of his domestic season, made the last of his 31 Test appearances for the Kiwis in 2013 and only made the reserve list for their 2015 World Cup squad.
"I've had a hugely enjoyable and memorable career in New Zealand," Franklin told Middlesex's official website. "It's been an absolute privilege to play for Wellington for over 15 years.
"Although this decision closes the chapter on playing for New Zealand again I know I've been incredibly fortunate to have spent over a decade playing international cricket.
"I'm really looking forward to being in a dressing room full of talented cricketers who will be wanting to help Middlesex win silverware and be a dominant force in county cricket."
Franklin, who has previously had spells in England with Gloucestershire, Glamorgan, Essex and Nottinghamshire, has the option of extending his stay at Lord's into a third year.
