(Reuters) - Christie's will showcase highlights of its summer season in London with a public exhibition of some of the most valuable lots from an art auction series expected to raise more than 300 million pounds.

Leading works by British landscape painter John Constable, 20th century titans Francis Bacon, Lucian Freud and Yves Klein and 17th century Dutch master Rembrandt will go on display from Tuesday until Thursday this week.

While brief, Christie's, the world's largest auctioneer, hopes the exhibition of museum quality works at its headquarters in King's Street, London, will add to the buzz surrounding the upcoming sales.

Such an initiative allows us to show the public works of art that have often rarely, if ever, been seen in public, said

Jussi Pylkkanen, president and chairman of Christie's Europe, Middle East, Russia and India.

In showing great art together, independent of age or category, the exhibition also presents a showcase of the collecting tastes and habits of many buyers in today's market.

Combined with Christie's arch-rival Sotheby's and smaller auction houses, London sales of art in late June and early July could approach $1 billion if the recent trend for record-breaking prices continues.

A handful of super-wealthy collectors is all that is needed to drive the value of a painting or sculpture to eight or even nine figures, and it was only in May that Edvard Munch's The Scream sold at Sotheby's for $120 million, an auction record.

As prices rise and the stress is increasingly on rarity and quality, owners of some of the best works of art still in private hands have been encouraged to sell, creating a virtuous cycle that has lasted for three years so far.

Analysts caution, however, that sluggish Chinese growth, a slowdown in buying from the Middle East and global economic uncertainty could weigh heavily on the buoyant sector.

Christie's is eyeing a number of artist records in its June-July sales.

Among the most prized lots on display is Constable's The Lock, the last of six celebrated large canvases by the artist still in private hands, which is expected to fetch 20-25 million pounds when it goes under the hammer on July 3.

When it was auctioned in 1990 it raised 10.8 million pounds, making it the most valuable British painting sold at the time - a record it held for 16 years.

Another artist whose auction record could fall is Jean-Michel Basquiat, whose Untitled from 1981 is set to sell for 10-15 million pounds, in range of the $16.3 million benchmark.

The painting will form part of the post-war and contemporary art evening auction on June 27 where Bacon's Study For Self-Portrait (1964) is on course to raise 15-20 million pounds and Klein's Le Rose du Bleu another 17-20 million.

A Bust of a Man in a Gorget and Cap by Rembrandt and dated 1626/7 is set to sell for 8-12 million pounds.

Pylkkanen said the upcoming summer season was set to become one of the richest and most valuable series of auctions in company history.

The low estimate of all the works on offer at Christie's is 310 million pounds, meaning that 2011's bonanza at the equivalent sales raising some 350 million pounds was beatable.

(Reporting by Mike Collett-White, editing by Paul Casciato)