General Motors

(GMGMQ)

says it will pull out of its 25-year old joint venture with

Toyota

(TM) - Get Report

in which the two companies shared a Fremont, Calif., manufacturing plant.

The operation was called New United Motor Manufacturing Inc., or NUMMI. It is ending because GM and Toyota "could not reach an agreement on a future product plan that made sense for both parties," said Troy Clarke, president of GM North America, in a prepared statement.

NUMMI will end production of vehicles for GM in August, GM said. It had produced the Toyota Corolla, the Toyota Tacoma pickup truck and the Pontiac Vibe. GM has said it will phase out the Pontiac brand.

"We have enjoyed a very positive and beneficial partnership with Toyota for the past 25 years, and we remain open to future opportunities of mutual interest," Clarke said.

However, Clarke said, NUMMI is expected to be a part of the "Old GM," or the group of assets slated to be sold off or shut down in bankruptcy court.