Shares in Xg Technology, a Florida-based wireless start-up, started trading today on the London AIM stock exchange.

Although Xg, which claims its low power wireless technology called Xmax could cover the US for a network installation cost of  $15m, has listed on the London AIM exchange, it is not raising any fresh money as part of the listing.

The company had hoped to raise £30m from the AIM listing in return for ten per cent of its equity which would have valued the company at £400m.

However, during the road show of potential investors, the company learned that there was no interest in investing at that level.

Nonetheless potential investors gave the company non-binding expressions of interest in buying £63m worth of convertible preference shares.

The shares of Xg which started trading today on the AIM were shares put up for sale by some of the seed investors. In the first few hours of trading they rose from $4.50 to $4.80.

The firm, which has already demonstrated the technology in the US, said the advantage of the technology, which can be operated in the 900MHz unlicensed band, is that it can be used to transmit data using low power RF signals which sit just above the noise floor and do not interfere with other signals operating in the band.

In a demonstration last year, the firm said it used a transmitter to broadcast a 3.67Mbit/s signal more than 18 miles using only 35mW of RF output power.

Voice-over-IP systems are expected to be an early application for the technology.

For more information see this blog about Xg Technology's flotation.