Sales of the U.S. Mint's new 2014-dated American Eagle gold coins were brisk on the first business day of the year, extending last year's strength boosted by gold prices' biggest annual decline in 32 years.

However, plenty of 2013-dated and other outdated gold coins at lower premiums in the secondary market could dent sales of U.S. gold coins this year, coin dealers said.

The U.S. Mint sold a total of 37,500 ounces of American Eagle gold bullion coins on Thursday, the first day the Mint began accepting orders of the 2014 model from its authorized dealers, U.S. Mint spokesman Michael White said.

Thursday's sales represent a quarter of the total in the entire month of January 2013.

U.S. coin sales tend to be highly seasonal, with the strongest performance at the start of the year as investors seek the most-recent mintage, and the fourth quarter usually being the quietest of the year.

In 2013, American Eagle gold coins sales totaled 856,500 ounces, a 14 percent increase year-over-year from 2012, while silver coin sales hit an all-time high of 42.675 million ounces.

However, gold's 28 percent drop last year that ended its 12-year bull run also suggests the availability of coins sold by investors back into the secondary market, which is expected to weigh down the Mint's 2014 coin sales.

"Buyers are looking for deals" as they seek lower-premium outdated coins, said Roy Friedman, executive vice president at Dillon Gage, a major U.S. coin wholesaler in Dallas which distributes to dealers and institutional investors.

Also pressuring 2014-dated coin sales is the fact that the Mint, beginning Jan. 21, will mix the 2014 coins with 2013-dated coins on a one-for-one basis when it sells to dealers until the 2013-dated inventories are depleted.

Michael Kramer, president of Manfra, Tordella & Brookes, a major U.S. coin wholesaler in New York, said he will most likely sell the older 2013-dated coins at a discount to the current-dated ones.

"Some people don't care about which year, but most of them do," Kramer said.

The U.S. Mint will accept orders of the American Eagle silver bullion coins beginning Jan. 13.