As usual, this season's ambitious schedule of Christmas Masses and carol services at St. Paul's Cathedral are free to worshipers. Yet for the tourists who line up for a Yuletide tour under Sir Christopher Wren's famous dome, the charge is the same as the rest of the year: admission at the door is 3 pounds, or about $4.50.

"People see this grand place and think we think we surely must be rich," said Robert Acworth, the registrar and chief administrator for the cathedral, which has dominated London's skyline since the end of the 17th century. "But in point of fact, we are not well-endowed, and the costs of upkeep are very high."The admission fee was first levied in 1991, and tourism, including gift shop sales, now counts for about 60 percent of the cathedral's income.

For officials at St. Paul's, like many of Britain's other great cathedrals, the levying of admission fees is just one of the innovative ways that Church of England leaders are now dealing with one of the more taxing consequences of their own rich inheritance: the soaring cost of sustaining these aging architectural monuments. In many cases, tourists outnumber the rolls of weekly worshipers.

By one count, 19 cathedrals are in financial deficit, and across England, church officials are faced with coming up with more than $45 million over the next five years to keep up basic restoration work on crumbling brickwork, worn tiles and sagging casements.

In a determined search for new sources of revenue, the stewards of many of England's 42 Anglican cathedrals have embarked on a variety of plans, from doing a better job of marketing their cathedrals' tourist potential to cutting their own commercial deals with local businesses and sponsors.

"It's an important but difficult question," said Stephen Jenkins, a spokesman for the Church of England in London. "How do you find ways to raise money to maintain these splendid old buildings, while not getting yourself tied into knots with the real missions of the church, which is ministry and mercy?"

Some of the ventures have been very successful. At the Bristol Cathedral, in the west of England, the cost of the cathedral's choral and musical programs is now underwritten by an annual grant from Nuclear Electric, the British energy conglomerate, in return for placing the company's logo and name in choral programs.

In Nottinghamshire, a $2 million fund-raising campaign to refurbish the Southwell Cathedral is being jointly sponsored and organized by officials at Britain's National Westminster Bank.

Other ideas have not been so well received. In Salisbury, a sponsorship arrangement between the cathedral and McDonald's foundered, after critics objected to a plan in which visitors to the cathedral who offered the equivalent of a $2 donation would receive miniature scrolls detailing its history and a coupon for a free Big Mac.

Even more fiercely disputed was a plan in the late 1980s by clergy at the Hereford Cathedral, who suggested selling off its ancient copy of the "Mappa Mundi," a 13th century map of the world.

The money was needed to make repairs at the cathedral, but the map was withdrawn from sale after a sharp public outcry, which in turn resulted in the intervention of John Paul Getty.

Getty, among others, put up several million dollars to build a separate building at the cathedral to house the treasure, but officials in Hereford say the church still does not have funds for critical repairs, including fixing crumbling masonry in the tower.

As a result of the growing financial pressure on England's great cathedrals, church officials did succeed in 1990 in convincing English Heritage, a government-supported agency, to make available a limited number of grants to help restore some of the buildings.

But for some in the church, including those advocates of hardball marketing schemes, there is ultimately no conflict between religion and business. At Ely Cathedral, which currently charges an admission fee to tourists, Michael Higgins, the cathedral dean, said the cathedral itself is a spiritual resource that must be maintained.

"The cathedral is a tool and if you neglect the tools of the Christian trade then of course you are neglecting the roots of the thing," Higgins said. "If we let the building go, there will no vehicle for inspiration or uplift."