It's gay times for California retailers — in both the old and new sense of the word.

Fashion stores and designers are celebrating the landmark California Supreme Court ruling legalizing same-sex marriages. The nuptials kicked into high gear across the state on Tuesday when county clerks began issuing marriage licenses. And, in what may be a setback for the antigay marriage wing, from wedding rings to suits and dresses to honeymoons, it turns out gay marriage is good for business — especially as gas and food prices rise and credit remains tight.

In the next three years, same-sex nuptials could generate as much as $683.6 million in revenue from weddings, hotels, marriage license fees, taxes and other tourism-related activities, according to a study by the Williams Institute on Sexual Orientation Law and Public Policy at the UCLA School of Law.

Nicole Miller saw bridal sales more than quadruple last week in her Los Angeles boutique. "Both brides are going in to buy wedding dresses," said Bud Konheim, the company's chief executive officer.

At Manika Jewelry on Maiden Lane in San Francisco, same-sex couples are shopping for artisan, one-of-a-kind wedding rings. "The increase in business is definitely noticeable," said owner Peter Walsh.

Recent sales include a pair of textured reclaimed gold Sarah Graham bands — $945 and $1,040 — and matching $300 wide silver rings by David Heston.

There is also marketing with a celebratory tone. For example, Macy's Inc. has run a full-page newspaper ad in metropolitan markets promoting its bridal registry and carrying this message: "First comes love. Then comes marriage. And now it's a milestone every couple in California can celebrate."

A window display at the San Francisco-based designer Wilkes Bashford's namesake specialty boutique downtown shows a female couple, one in a $1,895 sleeveless Catherine Regehr knee-length, cream-colored dress, and the other in a $3,655 Roberto Cavalli black skirt suit. The second window depicts two men, one wearing a $6,000 black Brioni tuxedo, the other in a $4,000 Belvest brown and black brocade tuxedo.

The windows carry signage that says "Celebrate Diversity" and include female and male couples in wedding attire atop cakes. "It's been tuxedos for the men and tailored dresses or suits for women," Bashford said. "We've had several couples call in and ask for appointments. These are new customers."

"You can't help but get excited for the couples," he said.

Spending on same-sex weddings among California residents is expected to be lower than nuptials for heterosexual couples, an average of $7,645 versus $30,580, which the Williams Institute attributed partly to less financial support for the event from family members. Out-of-state same-sex wedding expenses are anticipated to average $4,314.

The center, which filed a friend-of-the-court brief in the case that successfully challenged California laws limiting marriages to unions between men and women, estimated half of the state's 102,639 same-sex couples will marry by 2011 and more than 67,500 couples will travel to California to wed in that period. The conclusions were based on data from Massachusetts, the only other state to allow same-sex marriages, as well as the influx of couples who wed in San Francisco in 2004 when Mayor Gavin Newsom declared same-sex marriage to be legal.

The city has the highest percentage of same-sex couples — 6.9 percent — in California and has been at the epicenter of the movement to legalize their right to wed.

About 4,000 gay and lesbian couples from 46 states were married at City Hall in 2004, but the legality of those ceremonies was nullified in court. However, the state supreme court ruled 4 to 3 last month that same-sex couples have a constitutional right to wed. The court subsequently rejected arguments by conservative groups to stay its decision until voters consider a Nov. 4 ballot initiative to ban the unions. The ballot measure defines marriage as being "between a man and a woman."

In 2004, there wasn't much opportunity for couples to plan their wedding wardrobes, since Newsom's same-sex marriage declaration came without advance notice, and ceremonies were held only for a month before they were blocked. Now retailers have had more time to promote and prepare.

Tom Blumenthal, owner of the luxury gift emporium Gearys of Beverly Hills, said about a dozen same-sex couples have inquired about registering in just the last two weeks — some of them famous.

"These are major, major registries," said Blumenthal, declining to identify his celebrity customers.

French- and European-style china, as well as items displaying what Blumenthal described as "exceptional craftsmanship" are especially popular.

"This is definitely not just plain, gold-banded dinnerware like your grandmother had," he said. "We're loving it. It's added a whole new dimension to our clientele."

At the Monique Lhuillier boutique in West Hollywood, retail manager Kadie Bilodeau said: "The styles that have been more popular for the same-sex wedding are largely traditional, chiffon sheath-style dresses in silk, typically in the white and ivory family...as gay marriage becomes more commonplace, we'll all see an increase in related retail traffic."

In the Hayes Valley neighborhood near San Francisco City Hall, the window display at vintage boutique Ver Unica depicts a female wedding couple, one in an early-Seventies Geoffrey Beene cream and blue silk chiffon gown with butterfly sleeves, for $648. Her betrothed is wearing a sheer black wrap jacket dress trimmed in maribou feathers, $110, over a black slip and with a wide-brimmed black hat.

"It's the yin and yang" of marriage, said owner Cindy Spade. She said her wedding business flourished four years ago during the month that same-sex unions were allowed in the city.

Chris Ospital, the co-owner of MAC, a women's and men's fashion boutique in Hayes Valley, said wedding attire bought by couples included dresses by Tsumori Chisato and by Zero + Maria Cornejo. "We're getting some chic women who are buying suits as well," said Ospital, noting Dries Van Noten, Paul Smith London and Jil Sander were among the popular choices.

Designer Lily Samii, whose couture wedding gowns cost as much as $25,000, recently dressed a couple seeking an Audrey Hepburn look. One gown was short, the other long, with boat necks and open-V backs in a white silk honeycomb fabric, each costing $3,800. "The court decision will mean more business," Samii said.

Rafinity, a Santa Monica jewelry store that custom-made platinum and diamond rings for singer-songwriter Melissa Etheridge and actress Tammy Lynn Michaels, has had at least 10 to 15 same-sex couples shopping for wedding rings since the court decision. "When you figure we do an average of 20 to 30 weddings a month, then that's pretty substantial," said Ann Mangini, president and co-owner.

Mangini said she has considered advertising in publications targeting the gay and lesbian community, although she noted that there might be some reluctance from jewelers to go forward with investment immediately because the future of same-sex marriage is uncertain. "I am sure people are just starting to realize the economic repercussions, and that people are going to start spending money," she said.

Jeweler Neil Lane has not specifically targeted same-sex couples, but, he said, "My business has increased....It is a whole new audience. At the end of the day, sentiment is sentiment, and people want these things that people have always had. It just might be Mike and Jack instead of Mike and Mary."

Gay- and lesbian-oriented online jewelry resource Love and Pride may have experienced the largest windfall. Chief designer Udi Behr said sales in California skyrocketed as much as 600 percent in the last month. "Working with the gay community for the last four years, I can tell you that it is going to just increase," he said of same-sex wedding business.

New York-based Love and Pride has been a leader in supporting gay and lesbian causes and marketing toward the community. For instance, Love and Pride originally teamed up with Showtime's "The L Word" three years ago to sell a collection based on the series.

Behr doesn't believe there will be a rush by jewelers to engage gay and lesbian consumers. "There are a lot of industries that do cater to the gay community and the jewelry industry never really did anything," he said. "This is a very, very, very conservative industry. Things don't change fast, if at all."

In San Francisco, stylist Kristen Harper's firm, Wingwoman, is helping women pick fashions for their big day. One couple is dressing in suits — a navy evening suit by designer A.F. Vandevorst, for $1,250, with a silver shirt, paired with Prada heels, and a gray wide-lapel Paul Smith suit, $1,200, with a pink, blue and purple Etro shirt and Gucci loafers. Another couple are wearing off-white gowns — one strapless, the other long-sleeved — each about $2,000, by local designer Susan Hanley of Atelier de Modiste.

"They are like any people getting married," she said.

— With contributions from Anne Riley-Katz, Rachel Brown and Rosemary Feitelberg