A minister leading Britain's biggest-ever business delegation to India pressed New Delhi to liberalise its economy faster to spur trade between the two nations.

"We believe very firmly in open markets," said trade secretary Alistair Darling, a warm-up for Wednesday's arrival in India of British finance minister Gordon Brown -- billed in India's press as Britain's "prime minister in waiting."

Darling and Brown are heading a more than 150-member business delegation, the largest ever sent by Britain to its former colony.

"While we are the fourth largest investor in India and India the third largest in the UK, we can and should be doing better," said Darling, who landed Monday.

The chancellor of the exchequer's visit, his first to India, is seen aimed at boosting bilateral ties as well as his public profile ahead of his expected elevation to the job of premier later this year when Tony Blair steps down.

British analysts see the three-day trip as a chance for Brown to show he can be an international statesman and overcome charges by Britain's opposition Conservatives that he has ignored India as an "emerging economic giant."

He lands in the high-tech centre of Bangalore where he will speak Wednesday to India's premier business lobby, the Confederation of Indian Industry.

Later he heads to New Delhi where he will meet Premier Manmohan Singh and ruling Congress president Sonia Gandhi. He then goes to financial capital Mumbai.

Darling, tipped to succeed Brown at the exchequer, called India "one of the great opportunities for British business." Britain is India's fourth-largest trading partner but India represents just one per cent of British trade.

The focus of the mission, which contains 80 companies including accounting giant KPMG and pharmaceutical heavyweight GlaxoSmithKline, is on creating more investment openings for British business.

Darling said for India to reach average annual growth of 10 percent -- seen as vital for the country to make a significant dent in crushing poverty -- it needs more foreign direct investment.

He pushed India to fully open up its agribusiness and retail sectors, saying it would allow India to make the most of British expertise in those areas.

Indian Commerce Minister Kamal Nath said the country's achievements in liberalising its economy was due to its "calibrated form of reforms."

"We cannot apply a one-size fits all policy" with the huge disparities among India's 1.1 billion population, he said.

At the same time, "India has gone very far, we will continue to move."

The British visit comes as British mobile giant Vodafone's proposed takeover of Hutchison Essar, India's fourth-largest wireless operator, and Indian company Tata Steels ambitions to buy Britain's top steelmaker Corus, are in the spotlight.

Darling has said British firms are concerned about how much control they could have over ventures in India, which still restricts the size of stakes foreign firms can hold in many Indian sectors.