Supermarket giant Tesco is to double the size and availability of its Diamond Boutique lingerie range in response to "booming" sales.

The expansion of Diamond Boutique will come in January 2010, with Tesco Clothing CEO Terry Green pledging to offer more designs, more sizes and increased availability across the UK.

The aggressive move reflects Tesco's ambition to win a bigger slice of the UK lingerie sector, currently dominated by Marks & Spencer with a 26% market share.

The third collection of Diamond Boutique, created by Michelle Mone of MJM International, was launched yesterday (28 September), featuring eight new designs in materials including silk, satin and lace.

Mone, creator of the Ultimo bra, said of the planned expansion: "This is really fantastic news and testament to the fact that, despite the current climate, consumers are responding really well to value-for-money brands like Diamond Boutique.

"There's been a huge explosion in the sale of lingerie on the high street as people tighten their purse strings."

Tesco boasts that Diamond Boutique offers a combination of sophisticated designs and supermarket prices, claiming that a luxury silk bra normally retailing at GBP40 (US$64) costs only GBP14.