The Questar Corp. board of directors has approved a 49 cent-per-share quarterly dividend on the company's common stock.

Payment of the company's 184th consecutive dividend will be Dec. 17, 1990, to shareholders of record on Nov. 23, 1990. The dividend is the same as the previous quarter's and 1 cent-per-share higher than a year earlier.Questar subsidiary Mountain Fuel Supply Co. also declared dividends on two series of preferred stock: $2 per share on the 8 percent series and $2.15625 per share on the $8.625 series. The dividends are payable Jan. 2, 1991, to holders of record on Dec. 7, 1990.