Manhattan co-op prices are the highest in decade.

With demand, fueled by a healthy economy, briskly outpacing supply, prices of Manhattan co-op apartments soared last year to their highest levels in a decade, according to year-end findings published by the Real Estate Board of New York (REBNY) in its quarterly Cooperative Sales Report.

According to the market study, sellers, on the average, got 95 percent of their asking price in 1997 - an indication not only of strengthening demand but of growing competition among buyers for apartments. The largest price gains occurred for two-bedroom and studio co-ops, where the median price per room rose 15 percent and 13 percent respectively.

"You have to go back to before the last recession to find the level and intensity of buyer demand that we witnessed in 1997," said REBNY Executive Vice President Deborah B. Beck, who noted that the number of cooperative sales reported to REBNY last year totaled 2,599 - an increase of 9 percent over 1996 figures.

As was the case the year before, most transactions occurred in the $100,000 to $200,000 price range.

Hall Willkie, executive vice president of Brown Harris Stevens and chairman of REBNY's Residential Research Committee, pointed to another important indicator revealed by the study - median time on the market for listed apartments to the point of sale declined every quarter in 1997 from the corresponding period a year earlier.

"Product really turned over quickly last year, and that included virtually all unit types and sizes," Willkie said.

Here are some other key trends revealed in REBNY's year-end statistics:

* The median sales price for East Side pre-war apartments rose 6 percent from a year ago to $617,500, even though the median size of units sold fell from six to five rooms. East Side post-war co-ops experienced a 10 percent decline in median sales price, from $260,000 in 1996 to $233,500.

* With the median size of sold apartments falling from four and a half to four rooms, the median sales price for West Side prewar co-ops fell from $315,000 m 1996 to $280,000, but the difference between asking and selling prices rose from 94 percent to 96 percent, an indication that sellers were still getting their desired prices. The West Side post-war market was strong in 1997, with year-to-year median sales prices rising by 12% to $195,000.

* The Midtown co-op market improved significantly in 1997, as reported sales activity rose 24 percent to 540 transactions, while the time it took to sell these units dropped by 27 percent from 7.5 months in 1996 to 5.5 months last year.

* While reported sales traffic remains virtually unchanged from a year ago, median price per room jumped 23 percent to $72,929 in the Downtown market.

* Despite a sharp decline in the number sales reported, the median price per square foot rose 18 percent to $277 for lofts north of Houston Street, and 31 percent to $328 for lofts south of Houston Street.

* In the East Side pre-war market, co-ops took 13% less time to sell in 1997 as median time on the market fell from 6.9 to 6 months. Similarly, post-war time on the market also decreased from 6.3 months in 1996 to 5.7 months. West Side pre-war median time on the market fell 19 percent to 4.6 months in 1997. The post-war market also saw quicker turnover, as median time on the market fell from five months in 1996 to four months in 1997.

The Real Estate Board Cooperative Sales Report is the only fully documented survey of the city's co-op housing market, a sector whose transactions are not publicly recorded. The report pools and analyzes confidential sales and data supplied monthly by more than 20 REBNY member firms. The complete findings, distributed exclusively to those firms, help brokers assist their clients in setting realistic offering or sales prices.