The deal has been condemned by BBC Technology employees, who are members of the union Bectu, and they have voted to hold two separate strikes as a protest.
The first strike, on July 30 and 31, will coincide with blue-ribbon athletics and horse racing events, while the second, more damagingly, will affect the Olympic Games' opening weekend on August 13 and 14.
Bectu is contesting the September 1 2004 sale date, saying it was too close for proper negotiations to take place, and that the pension scheme and long-term contracts for its 1,400 members under the Geman electronics group were unsatisfactory.
Voting took place on July 9, and 84% of Bectu members voted for strike action.
BBC Technology workers are demanding a three-year guarantee on their current terms and conditions, plus a staged pay increase at 2.5% above inflation and reassessment of the pension scheme.
"Our members feel they are being rushed into key decisions about their futures, especially their pensions, without adequate information," Bectu general secretary, Gerry Morrissey, said.
He called on the BBC "to accept that we need months, not weeks, to deal with the mountain of details that our members are worried about".
The deal has been dealt another blow, this time by culture secretary Tessa Jowell, who will not begin to examine plans of the deal until September 6, a week after the sale is planned.
"Now we know September 1 won't happen, management should drop the idea of deadlines for the sale," Morrissey added.
If the deal goes ahead, it will be one of the biggest technology contracts in the UK. Siemens Business Services will buy the BBC division for £200m, take on its 1,400 staff and provide the corporation with IT support for the next 10 years, making the contract worth up to £2bn.
The BBC plans to plough the money raised from the outsourcing deal into providing innovative programmes and better services at the corporation.
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