Just days after BT said it was looking to re-enter the mobile consumer market, the wholesale arm of the UK incumbent announced it had bagged a ten-year deal to support the rollout of 4G services by Telefonica-owned O2.

Under the terms of the deal, BT is to build a new high-capacity transmission network, including extra backhaul capacity, to help O2 cope with rapidly increasing data traffic volumes.

“With the UK’s 4G spectrum auction complete, UK mobile data traffic is set to grow by more than 400 per cent by 2016,” said Adrian Di Meo, CTO of O2 UK.

When BT announced last week it was looking for a mobile operator partner to offer its own 4G branded services to UK consumers and enterprises, it sparked speculation that the UK incumbent would hook up with O2, the now Telefonica-owned business unit it spun off twelve years ago.

One of the reported attractions of cooperation between the two companies is that O2 and BT might be able to trade 4G frequencies. While O2 did not acquire any 2.6GHz spectrum in the recently-held UK 4G auction, BT did.

The wholesale agreement arguably offers even more scope for BT to negotiate with O2 on a return into the UK mobile consumer market.