SEPTA WILL experiment with restoring all-night subway service on weekends this summer, officials said yesterday.

The service will run on Fridays and Saturdays on the Broad Street Line and the Market-Frankford Line, said Kristin Geiger, a SEPTA spokeswoman.

She said the restoration of all-night subways - replaced several years ago with buses in a cost-saving move - is a test. If successful, it would continue after Labor Day.

The all-night service - which launches in mid-June - is actually part of SEPTA's proposed operating budget, which will start on July 1, Geiger said.

SEPTA's proposed capital budget totals $571.8 million, an 86 percent increase from last year - with $330.7 million in state funds thanks to the hike in the gasoline tax.

It includes $9 million in substation and power improvements, $43 million in bridge repair, and $58 million in communications and signal-system improvements.

A series of public hearings on SEPTA's proposed operating budget will start tomorrow at the Bucks County Free Library in Doylestown.

Meanwhile, negotiations were still underway with Transport Workers Union Local 234, which is now working without a contract.

Recent accusations have been made by SEPTA's largest union that the transit agency is misleading its workers over the issue of health-care costs.

SEPTA has proposed a 5 percent wage increase over two years, along with a 1 percent increase in union members' health-care contributions.