Finally, after almost 20 months, Diageo has got what it initially wanted in India. The company today (2 July) confirmed it now holds the majority of shares in United Spirits. This achievement, however, has cost way more than Diageo initially expected; to the tune of around US$1bn.

When the firm initially announced its plans in late-2012 to acquire the majority of United Spirits, Diageo said it would spend US$2.05bn on a 53.4% holding. Today, however, that spend - albeit for 54.78% of United Spirits - was revealed to have come in at $3.16bn.

The complexity of the transaction – which began with a 27.4% stake (bought at INR1,440 per share) that triggered a mandatory tender offer (MTO) – helps to explain partly the disparity. The MTO, which launched in May last year, was a failure, with only 0.4% of the Indian spirits firm's shares being tendered. Bear in mind, though, that the MTO was set at the same price of INR1,440. This, at a time when United Spirits' share price was hovering around INR2,500.

(The failure of the MTO was not a worry for Diageo, which had a commitment from United Spirits' former owner and second-largest shareholder, UB Group  to vote at Diageo's direction until either June 2018 or until Diageo owns over 50% of USL. The UK-headquartered company also already had control of board appointments.)

In April, when Diageo unveiled its plan to up its holding to majority control, the tender offer price was a far more attractive INR3,030 per share. Today, the share price sits at INR2,486. Hence, the successful purchase of a further 26%.

The importance of India to Diageo's future, then, is quite clear. While the other BRIC markets provide headaches for international spirits players, the company is hanging its future success firmly on India's peg. “India has now become one of Diageo’s largest markets,” said the group's CEO Ivan Menezes today. "(It) will be a major contributor to our growth ambitions.”

For $1bn more than intended, the company will be praying that Menezes is right.