Pact is facing a fresh membership crisis after it emerged that distributors BBC Worldwide and the Digital Rights Group have both left the trade body.

The corporation's commercial arm quit for financial reasons after a hike in membership fees. Pact recently changed its subscription terms so that members pay a percentage of turnover - which has sent the cost of membership for big companies soaring.

BBCW, which distributes a wide range of BBC shows such as drama Hotel Babylon, confirmed it had left Pact because it had become too expensive and no longer represented value for money. It is understood it was asked to pay many times more than it had done previously. Pact chief executive John McVay said BBCW's fees had increased to£75,000.

“It had got to the stage where we were propping them up more than the other way round,” said Abigail Hughes, BBCW senior vice-president, global digital. The company will still offer Pact its “advice and support”, a spokesman added.

Pact chief executive McVay told Broadcast he was not surprised that BBCW had left the alliance, but insisted that Pact was still offering BBCW good value despite the price hike. “Worldwide is a broadcaster's distributor and it gets its value across the piece,” he said.

“As a consequence of Pact's work, Worldwide can acquire distribution rights from production companies where previously they were hoovered up by the owner-broadcaster.There is a net benefit for Worldwide and I think all of that does deliver value.”

DRG was unavailable to comment on the reasons for its departure, although many sources confirmed it had also left because of the increased fees.

Pact would not reveal how much its distribution members pay, but said their fees are calculated in the same way as production company members'. Under the revised structure, independent production companies now pay an average of about£1,000 for every£1m of turnover up to a cap of£75,000.

The model was brought in to help ward off a funding crisis after Channel 4, ITV and Five all stopped paying levies to the group. Income from the three broadcasters had totalled more than£700,000 and made up 45% of Pact's£2m annual budget.

Last month, a raft of small to medium-sized indies including Zig Zag, Betty and Firecracker all turned their backs on Pact on the grounds that it no longer represented value for money.

They are all members of rival trade body, the New Independent Producers Alliance (Nipa), which was established in 2003 specifically to protect the interests of mid-sized producers.