Marriott Corp. declared a moratorium on most new construction projects Tuesday and said it would cut capital spending in half next year to $650 million because of uncertainties in the real estate and lodging markets.

Marriott said it believes the moratorium will last 12 to 18 months. Most properties now under construction will be completed next year, it said.William Shaw, chief financial officer, said the company was disappointed with a decision by Standard and Poor's Monday to put some Marriott long-term debt on CreditWatch with negative implications.

Marriott said it has stable cash flow and has already sold about $900 million in assets this year. It expects to sell an additional $700 million in assets in the next few months.

Marriott stock was up 87.5 cents at $11.625 in late afternoon trading.