Fitch assigned a "BB" issuer default rating to the subsidiary, Volt Delta Resources Inc. The ratings service also assigned a "BBB-" rating to the subsidiary's $100 million senior secured credit facility. The rating is one step above junk bond status.

The service also affirmed parent company Volt's "BB" issuer default rating, its "BBB-" rating on the company's $40 million senior secured revolving credit facility and its "BBB-" rating on the company's $12.9 million term loan.

All the ratings have a stable outlook.

Fitch said Volt's ratings reflect its "relatively stable operating performance" and its ability to diversify its sources of operating income to move away from the staffing services segment.

Volt shares rose 35 cents to $17.65 in electronic after-hours trading. During regular trading, the shares fell 25 cents to close at $17.30.