On his first visit to India since taking office in May, Cameron leads a delegation including six ministers and more than 30 senior executives from top UK firms, to show that Britain is serious about boosting economic exchanges with the Asian giant.
"I want this to be a relationship which drives economic growth upwards and drives our unemployment figures downwards," he will say in a speech to Indian businessmen, according to excerpts released in advance by officials.
He will say his visit to India is "as much a jobs mission as a trade mission".
India, a former British colony, belongs to the "BRIC" group of rapidly growing emerging economies along with China, Brazil and Russia.
Cameron's visit was not intended to yield any immediate deals between the two governments, but rather was the start of a long-term British strategy to focus relations with India on economic exchanges from which both sides stood to gain.
However, some of the executives on Cameron's plane will be hoping to return home with contracts in the bag. In particular, defence group BAE Systems has said it is close to clinching a deal worth about 500 million pounds ($775 million) to provide 57 Hawk training jets to the Indian air force.
Other business leaders travelling with Cameron include the CEOs of banking giant Barclays, infrastructure group Balfour Beatty, insurance firm Aviva and private equity firm 3i.
Cameron's coalition government says the British economy is too dependent on the public sector. It plans to slash public spending to reduce the budget deficit, which has swollen to a peacetime record, but critics say this will worsen unemployment.
The coalition says private businesses should be the engine of growth, and one of its strategies is to focus diplomatic efforts on fast-growing emerging markets to promote trade. On his way to India, Cameron visited Turkey where he made similar overtures.
In his speech in Bangalore, he will cite India's plans to ramp up investment in infrastructure, as well as its fast-growing retail and mobile telephone sectors, as opportunities for British businesses.
But he will also challenge India to "take on vested interests" and further open up its markets.
"We in Britain have welcomed your expertise in car manufacturing and steel production. But we want you to reduce the barriers to foreign investment in banking, insurance, defence manufacturing and legal services -- and reap the benefits," he will say.
With the World Trade Organisation's Doha round of multilateral talks making little progress, Britain sees a free trade deal between the European Union and India as the next big step forward. Cameron will say he is determined that such a deal should be reached before the end of the year.