J.C. Penney Co. Inc. (JCP) Thursday posted a huge jump in profit for the vital fourth quarter while Target Corp.'s (TGT) earnings rose slightly more than expected, helped by strong holiday season sales.

The retailers were among the first major U.S. chains to report results for the most important quarter of the year. Analysts were watching closely for any signs that retailers had sacrificed profit by slashing prices to boost sales during the fiercely competitive last six weeks of the year.

The fourth quarter generates the biggest portion of retailers' annual profit. Most retailers, including Target and J.C. Penney, operate on fiscal calendars that end in January.

Target, based in Minneapolis, posted a slightly better-than-expected 16 percent increase in quarterly profit, helped by the strong holiday season sales and fatter returns from its credit card business.

The next-largest discount retailer behind Wal-Mart Stores Inc. said profit rose to $939 million, or $1.06 per share, in the fourth quarter ended Jan. 28, from $809 million, or 90 cents per share, in the same period a year earlier.

Analysts, on average, expected earnings of $1.05 per share, according to Reuters Estimates.

Quarterly revenue rose 11.5 percent to $16.95 billion, while sales at stores open at least a year — a key retail measure known as same-store sales — rose 4.2 percent.

J.C. Penney reported a 65 percent surge in profit, helped by a tax benefit and strong sales at its department stores and online business. It also authorized a new $750 million common stock repurchase program and approved a plan to increase its dividend by 44 percent.

The company, which is working to transform its image from a frumpy, mid-priced retailer into a mainstream, fashionable store, reported fourth-quarter earnings of $551 million, or $2.34 per share, compared with $333 million, or $1.17 cents per share, a year ago.

On an operating basis, J.C. Penney reported profit of $655 million and earnings per share from continuing operations of $1.92, including 21 cents per share from a one-time tax benefit.

Analysts, on average, had been expecting the retailer to earn $1.63 per share, according to Reuters Estimates.

J.C. Penney said net sales rose to $6.2 billion from $5.96 billion, in-line with analysts' average target of $6.2 billion.