Google is in talks to buy a stake in Virgin Galactic, Sir Richard Branson's space tourism business, that would give it access to satellite launch technology, according to reports. The deal, estimated to be worth £17.8m, has not yet been sealed, but negotiations are thought to be at an advanced stage.

Sky News has reported that negotiations between the two companies have been going on for months and, according to anonymous insiders cited by the channel, the talks are likely to lead to a deal with two main elements.

First, Google would provide hundreds of millions of dollars to help fund a joint venture, with Virgin Galactic contributing the technology that it has developed while trying to build its space tourism business.

Second, Google would buy a small stake – likely to be around 1.5% – in the Virgin Galactic holding company. The sum of £17.8m would suggest that Branson's business is valued at around £1.2bn.

Virgin's space tourism business has suffered from a number of teething problems, but it insists that it will be ready to launch later this year. It could gain some much needed credibility from a deal with a firm like Google.

It emerged on Tuesday that Google has also set its sights on buying the satellite company Skybox Imaging. The $500m (£298m) acquisition will enable Google to improve the quality and immediacy of the imagery used in its digital maps, it was reported.

Skybox's satellite is already in orbit. This, along with the launch capabilities offered by Virgin's technology, would aid Google's plan to boost worldwide internet coverage, thus getting more people online reliably and potentially increasing its advertising revenues.