(Adds AGL comment; shares in last paragraph)
April 15 (Reuters) - Shares in Tilt Renewables Ltd TLT.NZ were halted on Thursday as the company held talks to improve a NZ$2.9 billion ($2.07 billion) takeover offer it agreed to last month, according to New Zealand's stock exchange.
The existing offer, at NZ$7.80 per share, will see the wind farm owner sell its Australian assets to Powering Australian Renewables (PowAR) and its New Zealand assets to Mercury NZ Ltd MCY.NZ , Tilt's second-largest shareholder. shares will remain in trading halt pending an announcement on the discussions, or until Monday, New Zealand's bourse operator said.
AGL Energy AGL.AX , which owns 20% of PowAR, had said it would contribute A$341 million towards the deal.
Tilt's largest shareholder, Infratil IFT.NZ , said on Thursday it awaited Tilt's update on the outcome of the discussions.
AGL declined to comment and Mercury did not answer calls by Reuters. Investment manager QIC, which owns the rest of PowAR, did not immediately respond.
Shares of Mercury fell about 2%, while Infratil cut early gains and was last up 0.7%. ($1 = 1.4013 New Zealand dollars)