* Shares down nearly 4 pct
* 4th-qtr comp sales, on constant currency basis, miss estimates
* 4th-qtr revenue, profit beat estimates (Adds analyst, CEO and CFO comment from conference call)
March 16 (Reuters) - Jeweler Tiffany & Co missed analysts' estimates for same-store sales in the fourth quarter and forecast a tepid full-year profit, indicating that its efforts to turn its business around are still gaining traction.
The results come as a surprise after Tiffany in January posted strong store sales for the holiday period and raised its full-year profit forecast.
The company's shares fell as much as 7.5 percent to a three-month low of $95 in morning trading on Friday.
Tiffany, which has suffered several quarters of declining sales, has been taking a number of steps to diversify its sources of revenue by introducing cheaper silver jewelry as well as everyday home items to appeal to a wider customer base.
Chief Executive Officer Alessandro Bogliolo said the investments were taking a toll on the company's earnings.
"Increasing investment now in certain areas, such as technology, marketing communications, visual merchandising, digital and store presentations ... will hinder pre-tax earnings growth in the near-term," Bogliolo said.
Former Bulgari SpA executive Bogliolo, who took over as CEO in October, said that the company has a "lot to do" with its products outside jewelry.
Tiffany recently renovated its New York flagship store, showcasing its new home items collection and opening a "blue box" cafe - modeled after its famous packaging - in an effort to draw more visitors.
Same-store sales, on a constant currency basis, rose 1 percent in the reported quarter, compared to analysts' estimates of a 2.8 percent rise, according to Thomson Reuters I/B/E/S.
"We still have a long way to go," Chief Financial Officer Mark Erceg said on a call with analysts on being asked about the company's same-store sales.
On a constant currency basis, comparable store sales in Europe fell 8 percent in the quarter, dragging down overall numbers.
"That was their strong hold," said Jane Hali, CEO of retail investment research firm Jane Hali & Associates. "It was the U.S. that was the problem not international, we never had to worry about international .... This is not good at all."
The company forecast a full-year profit of between $4.25 and $4.45 per share, compared to estimates of $4.37.
Net earnings fell to $61.9 million in the fourth quarter ended Jan. 31, from $157.8 million, a year earlier, largely due to a charge related to changes in the U.S. tax code.
However, excluding items, the company earned $1.67 per share, beating estimates of $1.64. Net sales rose 8.5 percent to $1.33 billion, edging past estimates of $1.31 billion. (Reporting by Aishwarya Venugopal in Bengaluru; Editing by Shounak Dasgupta)