Sigma Capital, the one-time technology investor 22% owned by Sir Tom Hunter, saw its shares soar by 44% as it unveiled a major housing venture which was endorsed by David Cameron.

Sigma's AIM-listed shares, which started the year at 6p, rocketed from 26.25p to 37.75p on news of the deal with Shariah-compliant Gatehouse Bank to support the roll-out of a £700 million programme of rented housing, beginning with 2000 homes in north-west England.

The deal comes more than two years after Sigma paid Sir Tom's West Coast Capital £347,000, paid for in Sigma shares issued at 16p, to acquire regeneration specialist Inpartnership, which had secured 10 to 20 year partnerships with the local councils in Liverpool, Salford and Solihull.

Sir Tom, who had co-invested alongside HBOS in Inpartnership, already held a 20% stake in Sigma which rose to 22%.

The new homes will be built on land procured and developed by Sigma. Last month the Edinburgh-based group reported a doubling of revenue to £2.2m but a £340,000 half-year operating loss, and said it had made progress on building a funding model for the rental sector. It is in negotiations for a development at Winchburgh in West Lothian involving 478 homes, and has said for the past two years that the end value of its potential projects was £2 billion to £3bn.

Gatehouse, an investment bank with a real estate portfolio worth more than £1bn across the UK and US, will deliver the equity element of the venture, and negotiations are in progress with banks to back the initial phase.

Sigma will generate revenues from asset management fees during both the construction and investment phases, and participate in the capital upside of the joint venture vehicle.

The Prime Minister said: "Sigma's joint venture with Gatehouse is brilliant news. The rental market is a vital asset to this country and this new investment will help to boost local economies, create jobs and deliver more homes for hardworking people."

Business secretary Vince Cable added his endorsement of the venture.

Graham Barnet, chief executive of Sigma, co-founded the group in 1996 as an investor in early-stage technology and raised more than £10m in a 2000 flotation at 125p, but over the next decade switched the group into property and sustainable energy investment.

He said: "We are delighted to have the support of the prime minister and the business secretary as we deliver this innovative joint venture model, supplying high quality homes in areas of the country where rental housing is in extremely short supply."