The coffee break refuses to die. As more workers flee their cubicles to get a latte fix, the office coffee machine has become a forgotten stepchild. Of people who drink coffee at work, the percentage that drink the in-house brew dropped to 52 percent last year from 64 percent in 2003, according to the National Coffee Association, an industry group.

Now, in hopes of keeping their employees on the premises - and sparing them the pain of a $4.95-a-day habit - some companies are trying new measures. First and foremost: upgrading the java.

Employers ranging from Microsoft Corp. to law firms and plumbing contractors are ditching their old suppliers and hot plates and switching to Starbucks Corp. and its competitors. Green Mountain Coffee Roasters Inc., a wholesaler based in Waterbury, Vt., says it saw a 29 percent increase in its office coffee sales in 2006. In the past year, offices have surpassed supermarkets and convenience stores as the company's largest customer type.

Many employers are also investing in single-serve machines that make everything from coffee and specialty espresso drinks to hot chocolate and allow employees to brew one fresh cup at a time.

Some employers say they are upgrading their coffee as an added perk for employees who are spending long hours at the office. "The people who love their Starbucks or Dunkin' Donuts are going to go no matter what, but when people are working around the clock, it's important to have coffee that they like and that tastes good and is convenient for them," says Norma Hanson, a business manager in the Boston office of the law firm Holland & Knight LLP, which recently installed machines by Flavia, a division of Mars Inc., on every floor.

Last summer, Microsoft upgraded from automatic-drip coffee to the Starbucks Interactive Cup Brewer - which brews single cups - on each floor of every one of its buildings nationwide.

"It's made coffee a topic of conversation," says John Montgomery, a group program manager on the company's Redmond, Wash., campus - especially among the "coffee snobs," or those who attend coffee tastings. "I learned a huge amount about coffee."

Montgomery conducted a personal taste test comparing the Farmer Brothers Co. coffee the company previously offered, the Starbucks blend in the new machines, and the Allegro French Roast he bought at a Whole Foods store and uses in the coffee maker he keeps in his office. He preferred the Whole Foods coffee. "What it came down to was the Allegro French Roast had a nice, nutty, smooth finish," says Montgomery, 39, who drinks 10 to 12 cups per day.

Paul Flaherty Plumbing and Heating Co. in Framingham, Mass., now offers employees 15 different flavors of Green Mountain coffee, ranging from the Nantucket Blend to hazelnut, made with a Keurig machine. Plumbers used to relax and have a couple of beers after work in the office break room. Now, some employees kick back with a cup of coffee instead.

It also helps increase worker productivity by keeping employees from making too many coffee runs, says Paul Flaherty, the company's president.

Before the company upgraded to specialty coffee a few months ago, two 10-cup coffee makers filled with bitter-tasting sludge were set up in the kitchen. "It was gross," says Jody White, a 37-year-old plumber. "You didn't know how long it had been sitting there."

Five years ago, "office coffee was definitely the ugly stepchild in the coffee industry," says Mike Ferguson, spokesman for the Specialty Coffee Association of America, a trade group with about 2,500 member companies. Now, he says, specialty roasters are increasingly selling their coffees to employers either directly or through office coffee services.

The trend first surfaced at larger corporations, but has now trickled down to a variety of industries - a result of the rising availability of single-serve coffee machines, more suitable for smaller employers. Some 140,000 offices use Flavia's single-serve drink machines, up from 40,000 in 2002. Keurig, a unit of Green Mountain, has seen sales of its single-serve machine to offices increase from 10,000 in 2002 to 45,000 in 2006.

Yet many employees who prefer to go off premises say a quick trip to the coffee shop gives them a much-needed break from work.

"It's a simple pleasure," says Matt Stitzer, a lawyer at Cleary Gottlieb Steen & Hamilton LLP in New York, who leaves his office every day after lunch to take a walk and buy coffee at the Starbucks in the lobby.