(Ricky Carioti/ The Washington Post)

Metro on Thursday suspended doing any new business with a Maryland contractor whose vice president is accused of attempting to bribe a transit agency official, according to a letter issued to the company, but work in progress will continue, the agency said.

A Maryland grand jury indicted Hardutt Singh, vice president of Hyattsville-based Potomac Construction, this week on a charge that he attempted to bribe the manager of Metro's Disadvantaged Business Enterprise Department on Dec. 16, 2016, according to the indictment, a copy of which was obtained Thursday.

"Indictment for bribery is a basis for suspension,” Metro chief procurement officer T. Suzette Moore wrote to the company Thursday. “The actions identified in the indictment raise additional concerns regarding Mr. Singh’s and Potomac Construction Inc.’s business practices that are so serious or compelling in nature that it affects Potomac Construction Inc.’s present responsibility to conduct business with [the Washington Metropolitan Area Transit Authority] in the future, and provide an independent basis for suspension” under Metro procurement policy.

The indictment against Singh in Prince George's County Circuit Court was announced Wednesday as part of a joint investigation by the FBI's Washington Field Office, Metro's inspector general, the U.S. Transportation Department's inspector general and the Maryland state's attorney, according to officials.

Metro said it has 15 open task orders with Potomac Construction amounting to about $17.5 million in contracts, with work in various stages of completion. The order applies to future jobs and places a hold on Potomac's ability to do business with the agency until legal proceedings are complete and Metro reevaluates its decision.

But work on the existing contracts, which include projects such as bike-and-ride facilities at East Falls Church and Vienna, swing gate modifications at 21 stations, and fire alarm upgrades at Glenmont will not be suspended, the agency said.

The indictment, obtained by The Washington Post on Thursday, identifies the employee Singh allegedly attempted to bribe as Erick Wilkes.

According to the indictment, Singh “did attempt to bribe Erick Wilkes for the purpose of influencing him in his capacity as manager of the Washington Metropolitan Area Transit Authority's Disadvantaged Business Enterprise Department.” The office is responsible for expanding opportunities for minority and woman-owned businesses to compete on federally funded transportation projects.

Wilkes is no longer with the agency, but his departure was unrelated to the case, according to a Metro official with knowledge of the separation. Wilkes could not be located for comment.

Maryland Assistant State's Attorney Joel Patterson is prosecuting the case, the IG's office said. Pressed for further details, Metro Inspector General Geoff Cherrington said the office does not comment on open investigations.

Reached by phone following the indictment, a woman who identified herself as Singh's wife said he was out of town and unavailable to comment.

Potomac has handled a number of jobs for Metro and most recently completed a $75-million rehabilitation of the Alexandria, Brentwood and New Carrollton rail yards. Metro said while that contract is still active, the projects are “substantially complete."

Potomac has 30 days to issue a rebuttal to Metro's suspension, according to the letter issued by Metro.

On its website, Potomac lists Metro as a top client, describing the extent of its activities with the agency:

"Potomac has extensive experience in all activities, including Design-Build, Bid-build and Job Order Contract for WMATA,” the site says. “In addition to overall project supervision and management, Potomac performs demolition, excavation, concrete paving, walls and walks, and site utilities, site preparations, site repairs, concrete for bus loops, retaining walls and foundations, expanding parking areas and foundations for major structures."

Singh is scheduled to be arraigned at 10 a.m. Sept. 21.

According to Metro, the open task orders with the company include:

-Pr. George’s County Bus Stop Concrete Pads (51 Locations) — 75 percent complete

-Alexandria Rail Yard Roof Replacement — 95 percent complete

-Locking of Station Swing Gates (Phase 2) — 21 Locations — 95 percent complete

-Environmental Compliance Tasks at Four Mile Run (FMR) Bus Division — 10 percent complete

-Environmental Compliance Tasks at Four Mile Run (FMR) Bus Division — 10 percent complete

-Environmental Compliance Tasks at Various WMATA Facilities — 10 percent complete

-Miscellaneous Roof Replacement Project (12 Locations) — 85 percent complete

-Glenmont Yard Fire Alarm Upgrades — 60 percent complete

-Flood Hardening Projects — Combined C02, C04, E05 — 0 percent complete

-Vienna Station Bike and Ride Facility — 0 percent complete

-AC Switchgear Room Rehab, Gallery Place (F01) — 10 percent complete

-CTF Fire Alarm Upgrade — 0 percent complete

-Huntington-SP Route — 5458 IB Pier Cap Weld Repair Work — 95 percent complete

-Replace Exterior Door, JGB Lobby — 0 percent complete

-East Falls Church Bike and Ride — 40 percent complete