ATLANTA – Plum Creek Timber Co. and Georgia-Pacific’s The Timber Co. said Monday they have delayed their merger by a week because of the trading suspension on the New York Stock Exchange last week.

Shareholders of both companies approved the $4 billion merger last month, creating the nation’s largest pure timber company.

The date was moved from Sept. 28 because Georgia-Pacific was required to give its shareholders notice of 30 “trading days” before it redeems common stock.

Georgia-Pacific will redeem the shares Oct. 5.

The Timber Co. shareholders will receive 1.37 shares of Plum Creek common stock for each Georgia-Pacific “unit,” consisting of one share of common stock of each of the six subsidiaries of the Atlanta-based company that control The Timber Co.

The Timber Co. manages 4.7 million acres of timberland in the United States and sells timber and wood fiber to industrial wood users.

Shares of Plum Creek, a Seattle-based real estate investment trust, fell $1.47 to close at $27.01 Monday on the New York Stock Exchange.

The Timber Co. shares were down $2.74 to close at $35.44. Georgia-Pacific shares fell $3.24 to $29.45 on the NYSE.