Shares of Chesapeake Energy Corp.          CHK,         +0.85%        edged up 0.1% in morning trading Monday, after S&P Global Ratings raised its rating on the oil and gas exploration company’s credit, citing a “favorable operational and financial track record” since merging from bankruptcy early last year. The rating moved up one notch to BB from BB-, but the new rating remained two notches deep into speculative grade, or “junk,” territory. The rating outlook is stable. The company has “grown production in a capital-efficient manner, made progress on the integration of two large acquisitions, and filled out its executive management team while keeping dividends and share repurchases within cash flows,” S&P Global said. The credit rating agency said it would upgrade Chesapeake’s credit if the ratio of funds from operations (FFO) to debt remain above 60% and if the ratio of positive discounted cash flow (DCF) to debt is positive for a sustained period. The stock has rallied 8.2% over the past three months, while futures for crude oil          CL00,         -0.66%        have lost 10.0% and for natural gas          NG00,         +5.28%        has tumbled 36.9%, and the S&P 500          SPX,         +0.78%        has shed 5.3%.