NEW YORK (Reuters) - Willamette Industries Inc. on Monday said it accepted in principle a sweetened $6.1 billion cash offer from larger rival Weyerhaeuser Co., potentially ending a 14-month takeover effort and creating one of the U.S. timber industry's largest companies.

Willamette's decision comes just 17 days after its board rejected a $55 per share, all-cash offer from Weyerhaeuser as inadequate. The decision to tentatively accept a new bid of $55.50 per share, comes on the heels of a Weyerhaeuser statement that 64 percent of Willamette's outstanding shares had been tendered in support of the $55 per share offer.

Portland, Oregon-based Willamette said in a statement that its board would reconsider the offer at its next board meeting, to be convened before the end of January.

Willamette also said it terminated discussions with Georgia-Pacific Corp. about acquiring that company's massive building products unit.