Constellation Brands has hired a company to investigate the distribution of shares in Canadian-based takeover target Vincor.

According to a report in the Canadian newspaper The Globe and Mail late last week, a Constellation spokesperson confirmed that the company has hired the firm to contact Vincor shareholders to see "who owns the shares," and find out who controls the major blocks.

It is thought Constellation may use the information to come back with a sweetened bid for Vincor.

The Globe and Mail quoted one portfolio manager who was approached about his firm's stake in Vincor, as saying: "I don't believe they (Constellation) will come back below C$34 for an official bid.

The manager added that the bid would have a low probability of success, and that whatever the bid Constellation "will leave room for a sweetener to ensure the success of the transaction".

Constellation launched a hostile takeover bid for Vincor International last month. The two companies initially met on 9 September, but Vincor's directors rejected Constellation's overtures.

Constellation offered Vincor's directors US$26.45 (C$31) per share, valuing the Canadian-based wine company at US$1.2bn, including approximately US$0.9bn of equity and the assumption of approximately US$260m of Vincor's net debt.

Rejecting the bid, Vincor said: "After a thorough review, Vincor's board of directors has determined that the C$31 price contemplated in Constellation's approach is inadequate and not in the best interests of shareholders in light of the future earnings prospects for the company and the significant synergies that Constellation would enjoy from acquiring Vincor."