Signet Group Plc, the world’s largest specialty retail jeweler, reported a 33% jump in first quarter profits on Thursday.

The UK-based firm, which trades as H Samuel and Ernest Jones in the UK and as Jared and Kay in the United States, made a pre-tax profit of $35.1 million in the 13 weeks to May 4, boosted by Valentine’s Day sales, the company said in a statement.

Signet continues to benefit from strong UK consumer spending and a rising market share in the United States, where sales contribute 71% of group profits.

Sales during the first quarter increased 13.5% to total $521.7 million.

Operating profit in the U.S., which accounts for 71% of annual sales for Signet, rose 16% to $40.4 million. In Britain, where Signet has 17% market share, operating profit improved to 2.4 million from 0.7 million this time last year, helped by strong demand for diamonds and watches.

“Our US business had a very encouraging quarter, capitalizing on its competitive strengths, and again increased market share,” Terry Burman, group chief executive said in a statement. “The trading environment in the US showed some improvement although economic indicators are still inconsistent and the outlook somewhat uncertain.”

Signet’s market share in the United States is estimated to be 7% and rising. It is the second largest U.S. jewelry retailer behind Zale.

JCK