HONG KONG — A vehicle license plate in Hong Kong sold at auction for 18.1 million Hong Kong dollars on Sunday, or $2.3 million, the highest price ever paid in the city. The plate carries the number 28, which in Cantonese sounds similar to a phrase for “easy money.”

The new owner of the plate was not immediately clear. The bidder, who also snatched the license plate 232 for $174,000, said he was representing another party, whom he did not name, according to Oriental Daily News, a Hong Kong newspaper.

The city introduced bidding for coveted license plate numbers in 1973, with the money going to charity. The most desired plates, which include the numbers 2 through 10 (1 is reserved for the police commissioner) and combinations of auspicious digits, are owned by some of the city’s richest and most prominent people.

In 1994, the jewelry, property and entertainment tycoon Albert Yeung bought 9 for what was then a record of $1.6 million. The most recent peak license price was $2.1 million for 18, in 2008.