William Hill, Britain's largest bookmaker, and partner GVC Holdings have agreed the terms of a raised £530m sterling takeover of online gaming firm Sportingbet.

William Hill makes most of its money in Britain but is expanding overseas and plans to take on Sportingbet's operations in Australia and Spain.

Smaller GVC would take on the company's operations in unregulated markets.

The cash and shares deal would be worth 61.1 pence per share of Sportingbet, up from a previous 52.5 pence.

Sportingbet said two weeks ago that the initial bid approach undervalued the company and had been reportedly holding out for at least 60 pence.

Shares in the firm were trading at 47 pence just before William Hill and GVC said last month they were considering a joint bid.

The latest proposal comprises 48.9 pence in cash, 1.1 pence dividend in cash and 0.0475 new GVC Holdings shares per Sportingbet share.

"Subject to reaching agreement upon its detailed terms and conditions, the board of Sportingbet has confirmed to William Hill and GVC Holdings that if such an offer were to be made, the board of Sportingbet would expect to unanimously recommend it to Sportingbet shareholders," the company said today.

The takeover panel has agreed to extend the deadline for a formal offer to be made until November 13.