Shares in Vodafone have fallen after the telecoms giant confirmed that it was in talks with Telstra to buy its New Zealand subsidiary, TelstraClear.

The firm claimed that its talks with Australian telecoms firm Telstra were ongoing and that there was no certainty an agreement would be reached.

It has been reported that the deal could be worth between £190 million and £255 million.

Vodafone’s shares fell after the announcement of the proposed acquisition and the stock is currently trading down 3.57 per cent at 167.45p at 9.00am.

TelstraClear, New Zealand’s second-largest telecoms company, was formed in 2001 by the merger of Telstra’s TelstraSaturn and Clear Communications.

For the six months to 31 December 2011, TelstraClear posted a pre-tax profit rise of 11 per cent to $69 million (£44.6 million), despite its revenue falling 4 per cent to $339 million (£219 million).

Vodafone also revealed that it is raising its stake in Invitation Digital, the parent company of Vouchercloud, to 57 per cent, up from the 21 per cent stake it took in May 2011.

Vouchercloud, a smartphone app that sends users offers, promotions and discount coupons for shops and restaurants, has just launched in Ireland. Vodafone intends to extend the scheme beyond the UK and Ireland over the next year.

Tobin Ireland, Vodafone’s commercial development director, commented, ‘Mobile couponing is set to grow rapidly across Vodafone's businesses as cost-conscious consumers increasingly turn to their smartphones to hunt for bargains and collect loyalty points.

‘We look forward to working more closely with Vouchercloud in future as m-commerce services become ever more central to consumers' daily lives.’