(ShareCast News) - Mobile commerce company Proxama has signed a long-term exclusive contract with Ubiquitous, which is the UK's largest provider of taxi advertising.Under the new contract, Proxama's marketing division, which focuses on connecting consumers to retailers and brands via mobile proximity marketing using Bluetooth low-energy beacons, will look to install beacons in up to 4,000 black cabs across the UK so passengers can receive context-relevant messaging.Proxama did not disclose any financial details of the deal but said the contract is for a three-year period.John Worley, Proxama's marketing chief, said: "This is an excellent high profile partnership for us and one which we believe is extremely well suited to proximity marketing. The average cab journey lasts around 20 minutes in London and is a natural time for people to check their smartphone for messages and new content. We look forward to seeing the customer reaction."At 0913 BST, Proxama shares were up 8.1% at 1.3239p.