NEW YORK, Dec 16 (Reuters) - Activist investor Jana

Partners urged Lamb Weston ( LW ) on Monday to replace board

members and top executives to improve its performance or else

put itself up for sale.

"Lamb Weston's ( LW ) Board and management have wasted the chance

to sustain and grow shareholder value in a high-quality

business," the hedge fund's managing partner Scott Ostfeld wrote

in a letter to the board. "There is urgent need - and strong

desire - for significant Board and leadership change at Lamb

Weston ( LW )," the letter continued.

If the board is unwilling to make "significant changes

needed to repair Lamb Weston ( LW )," then the company should put

itself up for sale at a time when strategic buyers are

interested, the letter said.

Lamb Weston ( LW ) did not immediately respond to a request for

comment.

Jana owns more than 5% of the roughly $11 billion company

and said in October that it wanted to see improvements in

operations and capital allocation, and possibly a sale.

In Monday's letter, Jana said Wall Street has reacted

positively to its involvement and that the company's value has

been increased by roughly $1 billion.

Holding company Continental Grain is working with Jana on

the investment and the partners have identified several industry

executives, including former Lamb Weston executive chairman

Timothy McLevish, as potential board candidates, Jana said

earlier.

The letter says financial and operating deficiencies have

cost Lamb Weston ( LW ) nearly $400 million in EBITDA over the last

2-1/2 years. It said increased spending had cut free cash flow

and dented confidence.

Jana also pointed to "questionable use and disclosure

practices" around the company's aircraft, citing heavy use of a

plane between its headquarters in Boise, Idaho, and Omaha,

Nebraska, 1,000 miles away. The letter said Omaha "appears to be

the CEO's primary residence."