(Updates with BBC quote)
LONDON, Nov 5 (Reuters) - Staff at Britain's state-funded broadcaster on Friday began the first of two 48-hour strikes to protest against changes designed to fill the gap in the BBC's pension scheme.
The broadcaster, a mainstay in British television and radio, was forced to transmit pre-recorded shows on several of its channels with Radio 4's flagship Today news programme among many cancelled bulletins.
The BBC is funded by a levy imposed on all households and its funding has been constrained by a government squeeze on public spending designed to rein in a record budget deficit.
"The BBC have proposed ripping up the current pension arrangements and replacing them with a pension scheme that will see staff paying more in contributions and working longer and getting less in retirement," the National Union of Journalists, which represents 4,100 BBC workers, said in a statement.
"As a result, NUJ members have been left with no choice but to strike to defend their financial futures."
The BBC wants to tackle a 1.5 billion pound ($2.42 billion) pension deficit by putting a cap on rises in pensionable pay at one percent after April.
Members of BECTU, a union representing technical and production staff, accepted a revised offer from the BBC as part of the pension changes.
BBC management defended the changes.
"These changes were necessary to deal with a pension deficit which, like many other schemes, is due to the performance of financial markets and the fact that people are living longer," BBC Director General Mark Thompson said.
"We have made clear this is our final offer and that we can make no more changes without imposing an unacceptable burden on licence fee payers."
The next 48-hour NUJ strike is scheduled for Nov. 15-16.
Separately, firefighters called off strike action planned for Friday -- when Britain commemorates, with bonfires and fireworks, the anniversary of a foiled 17th century plot to blow up parliament -- after negotiations with management on Thursday.
The planned industrial action stems from a dispute over shift patterns and a threat by management to sack all striking staff. The two sides have planned further talks on Nov. 16. (Reporting by Matt Falloon; editing by Keith Weir)