The company behind Petbarn and Greencross veterinary clinics has lifted its underlying half year profit 81 per cent.

Greencross made an underlying profit of $19 million in the six months to December 31, up from $10.5 million a year ago, as it opened new stores and expanded with its purchase of petcare retailer, City Farmers.

That acquisition weighed on its net profit in the half, which was down 31 per cent to $2.6 million.

Greencross shares gained 72 cents, or 8.5 per cent, to $9.18, its highest price in almost four months.

The company achieved like for like sales growth of 6.8 per cent in its Australian retail operations up to December, and continued growth of 6.6 per cent during January and early February.

It also remains on track to open 25 stores during the 2014/15 financial year.

Greencross lifted its fully franked interim dividend 2.5 cents to eight cents per share.

AAP