The Marcellus Shale Coalition has released guidelines designed to expand procurement opportunities in the shale-gas drilling industry for Pennsylvania's small businesses — along with testimonials from midstate companies about the success that can be achieved.

Published last week, the Pittsburgh-based coalition's recommended supply-chain practices state that member companies should:

• Establish procedures for buying from local companies that meet appropriate health and safety standards.

• Ask their business partners to do the same.

• Document their local economic impact and report it to the coalition.

"As an industry, we are fully committed to helping local businesses expand and hire," coalition President Kathryn Klaber said in a statement.

The coalition says it has hosted 15 supply-chain forums attended by more than 1,800 participants.

Supplementing the guidelines was a document titled "A Cascading and Positive Impact: Marcellus Shale Supply Chain Success Stories," containing testimonials from companies across Pennsylvania.

It quotes Derry Township-based engineering firm ARM Group Inc., which said it increased revenue 25 percent and added 50 employees thanks to Marcellus Shale work. It presents similar statements from Lancaster County engineering firm Rettew Associates Inc. and the Pepper Hamilton law firm, which has an office in Harrisburg.

The recommended practices are the second set released by the coalition. The first, from April, focused on site planning, development and restoration.