UPDATE 2-Toyota Calif. plant reaches closing deal with UAW

* NUMMI, UAW reach deal on Fremont, Calif., plant closing

* Toyota ending production on April 1

* Agreement requires ratification by union members (Adds details on Toyota, union efforts to save the plant)

DETROIT, March 15 (Reuters) - The United Auto Workers union has reached a tentative agreement for workers at a California plant Toyota Motor Corp (7203.T) plans to close within weeks, the joint venture that operates the plant said on Monday.

Toyota has been building the Tacoma pickup truck and the Corolla compact car at the plant in Fremont, California, which has operated for a quarter century as a joint venture between Toyota and General Motors Co [GM.UL].

Toyota plans to stop production on April 1 at the joint venture with GM known as NUMMI for the New United Motor Manufacturing Inc. It is shifting Tacoma and Corolla production to other North American facilities.

The closing comes at a difficult time for Toyota, which has been wracked by a series of recalls in the United States that have pressured sales of some of its most popular vehicles.

The shutdown also drew sharp criticism from the UAW and local political leaders with more than 4,000 jobs in jeopardy.

The automaker had seen a surge in U.S. market share over the past decade, that abruptly reversed at the start of 2010. A U.S. auto industry sales slowdown over the past four years also has left Toyota with excess U.S. production capacity.

Toyota has delayed plans to complete an assembly plant in Mississippi where it has planned to build the Prius hybrid, which is now built only in Japan.

GM, which emerged from a government-supported bankruptcy in July 2009, cut several brands including Pontiac and dropped its ownership interest in the NUMMI plant in its restructuring.

GM had built the Pontiac Vibe at the NUMMI plant, but ceased production of the car in August 2009.

NUMMI said on Monday the shutdown agreement is subject to a ratification vote by UAW workers at the plant and a vote probably will be set for later this week, NUMMI said.

Earlier in March, Toyota said it had committed $250 million to fund transitional support for the salaried and hourly workers at the plant. (Reporting by David Bailey and Bernie Woodall, editing by Gerald E. McCormick, Bernard Orr)