Wellington, March 9 NZPA - Mainfreight director Richard Prebble is selling shares in the logistics company, reluctantly he says.

The former Act Party leader sold 22,000 Mainfreight shares on market between February 2 and March 9 at an average price of $3.40 a share, according to a substantial security holder notice to the NZX today.

Notices since late last year show Mr Prebble has raised just over $1.1 million based on the average prices in the notices.

He has reduced his holding from 330,400 to 88,274 shares.

According to the earlier notices he sold 16,000 shares at an average $4.49, 52,500 shares at an average $4.72 and 151,626 shares at an average $4.76.

The prices Mr Prebble is selling at are well down from when the stock topped $8 a share in 2006.

Mr Prebble told NZPA the sales related to a matrimonial settlement.

Mainfreight has grown from modest beginnings into a global logistics company.

The New Zealand Shareholders' Association's bestowed its Beacon Award on founder Bruce Plested in 2008.