The Hershey Trust, the controlling shareholder of the US chocolate maker, has reportedly asked law makers in Pennsylvania to allow the company to potentially bid for Cadbury.

According to the Wall Street Journal, the trust has approached Pennsylvania attorney general Tom Corbett to get his approval for any move it makes for the Dairy Milk maker.

Sources familiar with the matter told the WSJ that, in recent weeks, at least one member of the trust's board had approached Corbett to see if he would allow Hershey to table a bid for Cadbury.

State law in Pennsylvania says Hershey must win the backing of the attorney general for any move the company makes that could lead to the trust losing control over the business.

The trust, which owns a 30% equity stake in the company but 80% of the voting rights, was set up by Hershey's founder to look after the interests of the Milton Hershey School, which is run for under-priviledged children.

Hershey is yet to make a formal offer for Cadbury; so far, only Kraft Foods has tabled a bid for the UK confectioner.

Last week, Hershey confirmed an interest in Cadbury and said it was mulling a possible bid for the business.

Hershey's announcement was followed by an separate statement from Ferrero confirming the Italian confectioner was in the "preliminary stages of evaluating its options in respect of Cadbury".

Speculation has centred on whether Hershey and Ferrero would lodge a joint bid for Cadbury - or whether the US group would go it alone.

Cadbury shares stood at 805.5p at 15:45 GMT this afternoon, up 0.3% on the day. On Monday (23 November), Cadbury's shares closed at 814p.