WASHINGTON (Reuters) - U.S. consumers have tightened their belts in the wake of the global financial crisis, which if sustained would break a trend of steady increases in the consumption rate since the 1980s, according to an International Monetary Fund study published on Monday.

The rate of U.S. household consumption is likely to fall from its current level, causing the saving rate to rise to about 6 percent of disposable personal income from nearly 5 percent in 2009, the study found.

Compared to years of over-consumption by Americans, fueled by a credit boom, the IMF said the savings rate implies a decline in U.S. private-sector demand in the order of 3 percentage points of gross domestic product.

Using economic simulations, the IMF said U.S. household consumption and saving rates are expected to settle at 89.5 to 91.5 percent and 5 to 7 percent of disposable income, respectively, over the next several years.

Similar levels of consumption and savings rates were last seen in the early 1990s, it said.

The IMF said the future of U.S. consumption had “tangible macroeconomic implications” for the U.S. economic recovery and for global growth and current account imbalances.

“If U.S. private-sector demand remains at a subdued level, global economic growth will be less vigorous than otherwise, and the distribution of current account balances will need a realignment -- a smaller deficit in the U.S. will have to be matched by smaller surpluses or larger