Tiffany & Co.'s new Paper Flowers collection.

Worldwide sales growth, a comparable sales gain and an increase in gross margin helped Tiffany & Co. beat Wall Street’s second-quarter earnings estimates, which also led the company to raise its full year outlook.

For the three months ended July 31, net income rose 25.8 percent to $144.7 million, or $1.17 a diluted share, from $115 million, or 92 cents, a year ago. Net sales increased 12.1 percent to $1.08 billion from $959.7 million. The company said comparable sales rose 8 percent.

Wall Street was expecting EPS of $1.01 on sales of $1.04 billion. Investors sent shares of Tiffany up 4 percent to $135 in pre-market trading at 7:39 a.m.

Alessandro Bogliolo, chief executive officer, said, “We are pleased with our sales and earnings growth and the strength and breadth of the results in the first half of 2018, but it’s worth noting that strategic investment spending is increasing for the remainder of the year, as expected, which is intended to support longer-term sustainable growth.”

One initiative is the firm’s recent announcement that it would remodel its Fifth Ave.’s flagship building in Manhattan, a project that is expected to last several years.

The ceo added, “We believe that the thoughtful combination of making short- and long-range strategic investments is necessary to achieve the full growth potential of this legendary brand.”

For the quarter, the company said net sales in the Americas rose 8 percent to $475 million, while comps rose 8 percent. It attributed the growth primarily to higher spending by local customers. Sales in Asia-Pacific rose 28 percent to $301 million, which included a comp sales growth of 12 percent. In Japan, sales rose 11 percent to $155 million, and comps rose 9 percent. And in Europe, sales rose 5 percent to $121 million, although comps fell 1 percent. Other net sales slipped 21 percent, mostly due to a reduction in wholesale sales of diamonds.

The company said that gross margin rose to 64 percent in the second quarter, compared with 62.5 percent in the same year-ago period. The increase reflected lower wholesale sales of diamonds, favorable product input costs and sales leverage on fixed costs, partly offset by increased investment spending, Tiffany said.

The company guided fiscal 2018 diluted earnings per share to $4.64 to $4.80, up from a previous forecast of $4.50 to $4.70. Net income and earnings per share for the third quarter were estimated to be lower than year-ago figures. Third quarter estimates take into account the company’s plans for increased investment spending over the balance of the year.

The company recently introduced its Paper Flowers line, a floral collection in platinum and diamonds that it said is moving toward full global distribution.

Bogliolo said plans for the remainder of the year include a “special focus on product personalization, high jewelry, a whimsical holiday campaign and the unveiling in North America of Tiffany True, an innovative diamond ring concept.”