Sales of new homes fell unexpectedly last month after rising for five straight months as the effects of a temporary tax credit for first-time owners started to fade.

The Commerce Department said Wednesday that sales fell 3.6 percent to a seasonally adjusted annual rate of 402,000 last month from a downwardly revised rate of 417,000 in August. It was the first time since March.

Despite the decline, the market is still 22 percent above the January figure when sales reached the bottom, though 70 percent below its peak recorded in July 2005.

The median sales price of $204,800 in September 9.1 percent below last year’s $225,200, but 2.5 percent August's $195,200. The average sales price rose to $282,600.

Analysts attribute the decline to the potential expiration of the new home-buyer tax credit. The tax break worth up to $8,000 for eligible first time home buyers is set to expire at the end of November but Congress is expected to extend and expand the program, but the terms are still being debated.

The seasonally adjusted estimate of new homes for sales at the end of September was 251,000 units which represent 7.5 months at current sales rate. This is 4 percent below August and the lowest inventory in 27 years.