Like most stories in the Daily Telegraph, today's front-page announcement on the future of the newspaper was brief and to the point.

Under the byline of Lord Hartwell, whose family has owned the paper for nearly six decades, a short four paragraphs explained that a need for "extra finance" had resulted in control of the Telegraph company being turned over to Conrad Black, a Canadian businessman.

"My family," Hartwell wrote, "previously controlling 60 percent, will be reduced to a minority."

The story confirmed what had been rumored in the pages of Daily Telegraph competitors for weeks. The last of Britain's traditional, family-owned major newspapers had gone the way of so many before it -- out of money and sold to conglomerates, some of them controlled by foreigners.

The news may have sent shudders through many of the more than 1 million British households that depend for daily reassurance on the gray countenance and conservative views of the 135-year-old newspaper and its younger Sunday version. But final word of the Telegraph sale was inevitable for others who have watched Fleet Street, the traditional London home of the British press, fall on increasingly hard times through years of labor difficulties, financial losses and technological backwardness.

Some even saw it as part of an encouraging trend that what is also known here as the "Street of Shame" is on its way back up to solvency.

From Australian Rupert Murdoch's takeover four years ago of The Times and The Sunday Times, to Roland (Tiny) Rowland's addition of The Observer to his southern Africa-based Lonrho mining empire, to the flamboyant and contentious operation of The Mirror under Robert Maxwell's Pergamon Press conglomerate, newspapers suddenly have become part of big business in Britain.

Half of Fleet Street now is planning major plant expansions, many of them in London's new East Docklands development zone. Computer technology that has long been standard at U.S. operations is moving quickly into a British industry that has been burdened with turn-of-the century technology.

Much of the change is due to the emergence on Fleet Street of Eddie Shah, the owner of several small newspapers outside Manchester who gained nationwide fame in 1983, when he took the powerful printers' union to court for unlawful strike action and won.

Faced with competition from Shah, who now says he can produce a quality national tabloid for far less money and with much lower advertising rates, others have begun to follow his lead. Both Maxwell and Murdoch are in the midst of major labor disputes, demanding no-strike contract clauses and a free hand in manning decisions.

This morning, Mirror Group unions were reported close to accepting what Maxwell called a "historic agreement" that would eliminate 2,000 of his 6,000 employes.

Not all British newspapers have been as hard-nosed, or as successful in dealing with the unions. The Guardian, for example, frequently fails to appear on newsstands.

The Daily Telegraph, under Lord Hartwell, tried some changes of its own, but ultimately failed. In the view of experts here, it was neither tough enough with the unions nor clever enough in its management or modernization to overcome falling advertising revenues and increased costs.

"What happened," said Charles Wintour, editor of the newspaper trade publication U.K. Press Gazette, "was that the Telegraph management was very slow to react to the new situation in Fleet Street."

Since it first published in 1855, the Telegraph has been a tradition here. "There has always been a Daily Telegraph in the same sense that there has always been a Salisbury Cathedral, a British Museum . . . and a Stonehenge," wrote a Guardian columnist recently. "If the Daily Telegraph ceased to be itself, I should feel immeasurably deprived."

"Itself" is a fairly staid, drab and crowded daily compendium of all the news that's fit to print about Britain and the world. Stories, often packed two dozen to the front page, run from a paragraph to a column, with an often-empty white space left on the bottom for "Late News." The paper's editorial support of the currently governing Conservative Party has earned it the nickname "Daily Tory-graph."

Lord Hartwell, 74, born Peter Berry, served a long apprenticeship in the newspaper business before he took over the Daily Telegraph -- owned by his family since 1928 -- following the death of his father in 1959. A tall, taciturn man, he has a reputation in Britain for journalistic integrity and good treatment of his employes.

"On the whole," said one veteran London journalist, "he has always been considered rather benevolent, . . . but he fell victim to his own vice. The Telegraph management was always known as the softest touch on Fleet Street."

Hartwell, the journalist said, "just wouldn't sack anybody."

Although last year's figures show the Daily Telegraph with the highest circulation, at 1.26 million, of Britain's "serious" national dailies, by the middle of 1985, Hartwell was known to have his back to a financial wall.

In June, the paper put together a $150 million rescue package from financial institutions, some of Hartwell's own money and $17 million from Canadian entrepreneur Black. Black's deal also included 14 percent of the stock in the Telegraph company, and an option for first crack at purchasing a controlling interest if it ever came on the market. The company proceeded with plans to move into costly new printing plants in Manchester and London, allocated severance pay for excess employes and predicted that six-month figures due out last month would show a modest profit.

By mid-November, stories began to appear -- most notably in Murdoch's Times and Sunday Times -- that losses had continued and Hartwell would be forced to sell the family business. According to one unconfirmed account -- the six-month figures still have not been released -- among the problems was the discovery by auditors of an extra 300 production staff on the payroll beyond the initial count. The additional severance cost alone was estimated at nearly $20 million.

On Nov. 19, management announced a freeze on all pay increases, including a 5 percent rise authorized for the editorial staff.

Hartwell reportedly made several last-minute attempts to keep the newspapers under family control. The family, Wintour said, just "got caught with their pants down. A year ago, it could have been sold for 100 million pounds, and they could have left it in good hands . . . It's a tragedy but the whole thing was very badly handled."

Hartwell promised in today's story to reveal full details of the sale to Black in Friday's editions of the paper. According to reports today, Black has brought his ownership to 50.1 percent for a fraction of Wintour's 100 million pound estimate of a year ago.

So far, there are no indications of any changes planned under the new management. Hartwell, as a minority shareholder, is to remain as editor in chief and chairman, and there are rumors that Black has invited Andrew Knight, currently editor of the Economist, to head a new Telegraph editorial team.

Although Black owns several small Canadian publications, they do not reflect any particular editorial bent. In the British press, he is described only as the "wheeler-dealer, tycoon" manager of a string of Canadian businesses and controller of two investment holding companies.

His political views are said to be conservative to right-wing. In a letter of complaint about a story on President Reagan to the Spectator magazine here last summer, Black reflected that "I have generally been disappointed by the lack of integrity and serious analysis in British (and most foreign) reporting of American affairs. This was one of the lesser reasons why I recently purchased a sizable interest in the Telegraph."