SAN FRANCISCO, California - Levi Strauss & Co, which pioneered the making of jeans, may be going public for a second time, according to a report by CNBC.

Quoting sources familiar with the jeans-maker's plans, CNBC said the San Francisco-headquartered company is working on an IPO.

The proposal is to raise between $600 million and $800 million, with completion expected in the first quarter of next year, CNBC said citing sources.

The numbers being worked put the 145-year old companys value at around $5 billion.

Levi Strauss refused to comment on the report, saying it it does not comment on marketplace rumors or speculation.

The company went public once before, in 1971, but soon after was privatised by members of the Strauss family.

Demand for jeans is buoyant. The company reported a 10% increase in sales revenue to $1.39 billion in the last quarter, resulting in a net income jump of 44%.

Levi Strauss, who had been born in Bavaria in 1829 made his way to the United States. He journeyed to San Francisco in 1853 when he heard of the goldrush. He established a wholesale dry goods business under his own name and served as the West Coast representative of the familys New York firm. Strausseventually renamed his company Levi Strauss & Co.

Around 1872, Strauss received a letter from one of his customers, Jacob Davis, a Reno, Nevada tailor. In his letter, Davis disclosed the unique way he made pants for his customers, through the use of rivets at points of strain to make them last longer. Davis wanted to patent this new idea, but needed a business partner to get the idea off the ground. Strauss was enthusiastic about the idea. The patent was granted to Jacob Davis and Levi Strauss & Companyon May 20, 1873; and blue jeans were born.