NEW YORK (TheStreet) -- Shares of Bill Barrett Corp. (BBG) are declining by 0.85% to $9.28 in pre-market trading on Thursday, as Keybanc downgraded the stock to "sector weight" from "overweight."

The firm does not have a price target on the Denver-based oil and gas company.

"We believe the likelihood of disappointing upcoming well results combined with a full valuation could limit further outperformance, especially as we see the need for $60/bbl oil price to catalyze an increase in activity given high leverage and wide cash flow deficits post-2016 as hedges roll off," Keybanc wrote in a note.

Bill Barrett's valuation appears full as it is the firm's best performing stock in its coverage universe year-to-date.

Keybanc no longer believes the valuation can support further outperformance.

Separately, TheStreet Ratings Team has a "Sell" rating with a score of D on the stock.

The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, disappointing return on equity, weak operating cash flow, generally high debt management risk and generally disappointing historical performance in the stock itself.

Recently, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.

You can view the full analysis from the report here: BBG