New England venture-backed companies have yet to complete an initial public offering this year — the first time since 2003 that no such IPO has closed by midyear.

At least five VC-backed companies had registered to complete IPOs this year, but with 75 percent of the companies that went public last year seeing their shares trading below the issue price, companies in registration have been holding off.

Last year, nine local VC-backed companies had completed IPOs by midyear, and 20 went public in all of 2007. Nationally, the second quarter was the first three-month period in 30 years of tracking by the National Venture Capital Association that no VC-backed company went public.

Last year, 25 IPOs had been completed in the second quarter.