Chevron posted a third-quarter profit that missed Wall Street estimates by a wide margin, sending its share price down in premarket trading.

Oil company earnings have slumped from record year-ago levels as crude prices eased and higher costs crimped refining and chemical profits. Results remain strong by historical standards but are well off year-ago levels.

The company earned $6.5 billion, or $3.48 per share, compared with $11.2 billion, or $5.78 per share, in the same period last year.

Adjusted profit was $3.05 a share, compared with analysts’ estimate of $3.75 per share, according to LSEG data.

Shares fell 2% to $151.14 in premarket trading.

Results come after Chevron agreed to buy U.S. Hess for $53 billion to expand its shale and deepwater oil production. In addition to Hess, it acquired shale oil and gas producer PDC Energy and a majority stake in ACES Delta, a hydrogen storage firm.

The earnings miss came after the company warned that maintenance in its oil and gas production and refining businesses would hurt results. It also suffered a setback in a Kazakhstan project with an about six-month delay in expanding oil and gas production at its Tengizchevroil operation.

“It is going to be a rough day for CVX shareholders,” wrote RBC analyst Biraj Borkhataria, who described the earnings shortfall as “disappointing,” but blamed it on non-recurring items.

Capital expenditures during the quarter rose more than 50% to $4.7 billion, in part due to the acquisition of ACES Delta. Total cost for the Tengizchevroil expansion project is expected to rise by $1 billion.

Profit from pumping oil and gas fell about 38% to $5.76 billion in the quarter from $9.3 billion a year ago. But volume rose to 3.15 million barrels of oil and gas per day (boed) on its acquisition of PDC Energy. It pumped 3.02 million boed a year ago.

Oil prices recently rebounded from a mid-year slump as tighter supplies drove up crude prices. The company’s cash flow from operations fell to $9.7 billion, from $15.3 billion a year ago.

Its refining business posted an operating profit of $1.68 billion, down from $2.53 billion a year ago. Gains from its U.S. refining business were offset by weakness overseas, where margins and inputs fell.