"Now I want to see thousands more jobs created in Britain, and of course thousands more in India through trade in the months and years ahead. This is the core purpose of my visit," Cameron said.
Hours before his speech, Vince Cable, the British business secretary, announced that the UK would allow the export of its civil nuclear technology to India, mirroring an agreement the United States made with India in 2005.
The delegation will now head to New Delhi, where Cameron would hold talks with Manmohan Singh, his Indian counterpart, on Thursday.
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.
"...UK needs India more than India needs UK now."
Narayanan Madhavan, associate editor, Hindustan Times newspaper
"India is ... an emerging economy seeking and giving opportunities in return, and I might add that probably [the] UK needs India more than India needs [the] UK now," Narayanan Madhavan, an associate editor at the Hindustan Times newspaper, told Al Jazeera.
British exports to India declined over the past year, Madhavan said, so Cameron is likely looking to boost trade.
Indian newspapers are focusing on the massive purchase of scores of British fighter jets and the sheer size and stature of Cameron's delegation, which includes the finance, defence and foreign ministers, Madhavan said.
The delegation also includes scores of British executives, some of whom will be hoping to return home with contracts.
Defence group BAE Systems said on Wednesday that it had won a $779m order to supply 57 Hawk trainer jets to India's military.
Rolls-Royce announced separately that it had inked a $312m deal to supply Adour engines for the aircraft, which India plans to use to train its pilots for flying supersonic combat jets such as the Jaguar.
Cameron's government has said 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, and he will continue his trip to China.
"In Britain, we're waking up to a new reality," he wrote in The Hindu newspaper.
"Economic power is shifting - particularly to Asia - so Britain has to work harder than ever before to earn its living in the world. I'm not ashamed to say that's one of the reasons why I'm here in India."