Woolworths and its home improvement partner Lowe's Companies have injected another $90 million into their loss-making joint venture – the fourth capital injection this year – even though Woolworths has cut back spending on Masters stores.

Documents lodged with the Australian Securities and Investments Commission this week show that the Hydrox Holdings joint venture issued 90 million new shares at $1 each – 60 million to Woolworths and 30 million to Lowe's – on August 28, the same day that Woolworths revealed that losses from home improvement jumped 33 per cent to $224.7 million in 2015.

Woolworths and Lowe's invested $3.5 billion in its hardware experiment. Credit:Glenn Hunt

Losses at Masters blew out from $176 million to $245 million, while profits at Home Timber and Hardware rebounded 198 per cent to $20.9 million, boosted by recent acquisitions.

Annual accounts lodged by Hydrox Holdings show that while revenues rose 22 per cent to $1.87 billion in 2015 as Woolworths opened new Masters stores, the cost of sales rose at a similar rate, and operating costs including administration and wages rose 24 per cent, leading to mounting losses.