All out industry war has broken out over the wholesale prices BT is allowed to charge rivals.

The Competition Appeal Tribunal (CAT) has referred an appeal by BT over proposed price controls to the Competition Commission (CC).

BT is challenging regulator Ofcom over the prices it will allow its BT Openreach division to charge other telcos for access to its infrastructure, to deliver their own services to customers.

Joining the fray are Sky, TalkTalk and Everything Everywhere which consists of the T-Mobile and Orange brands. All these companies have lodged their own appeals on the pricing formula.

The price controls relate to wholesale charges for telephone and broadband services delivered to homes and businesses over BT's copper network under the local loop unbundling and wholesale line rental regimes.

The charges were expected to cover the period 2012-2014 and were announced by Ofcom in March 2012.

BT is challenging Ofcom's decision on a number of grounds and the CC has until 29 March 2013 to determine the pricing issues.

Sky and TalkTalk have been granted permission to intervene in BT's appeal and BT has been granted permission to intervene in the Sky/TalkTalk appeal. Everything Everywhere is intervening in both appeals.

Under the 2003 Communications Act, if decisions by Ofcom are appealed to the CAT and include a price control matter, then this matter must be referred to the CC for determination.

Earlier this week BT announced plans to recruit an additional 400 broadband engineers, to be filled mostly by ex-armed forces personnel.