The owners of a string of high street fashion names yesterday unveiled plans to merge, creating what would be one of the UK's largest women's clothing presences.

Mosaic Fashions, which owns the Oasis, Karen Millen, Coast and Whistles chains, said it was planning a tie-up with rival Rubicon Retail, the company behind Warehouse, Principles and the footwear operation Shoe Studio.

Mosaic said it had signed a non-binding letter of intent to merge with Rubicon, with plans in place to complete the deal within three months.

The new company is likely to a have a combined turnover of over £800 million, Mosaic said.

Although Mosaic is listed on the Icelandic Stock Exchange and has a presence in Reykjavik, both companies have their headquarters in London.

But it is understood that there are no immediate plans to merge the offices and cut jobs if the tie-up goes ahead.

Mosaic has over 6,500 staff, operating 633 stores and concessions in the UK, Ireland other parts of Europe and the United States, as well as having franchise stores in 23 countries and 70 department store concessions in China through a joint venture.

Rubicon is a similar size, with 6,404 staff across 817 outlets primarily in the UK and Ireland.

Mosaic's chief executive Derek Lovelock, who will run the merged business, said: "Rubicon has a strong portfolio of fashion brands which operate in a sector of the market that we know well."

His counterpart at Rubicon, Don McCarthy, who is set to stay on as an adviser, added: "The enlarged group would have successful and differentiated fashion clothing and footwear brands, excellent prospects for further growth and for enhancing value for shareholders."

The combined company is set to trade under the name Mosaic Fashions and retain its stock exchange listing.

If Mosaic investors back the tie-up at a planned meeting, a shares and cash exchange will be carried out to combine the two operations.