(Adds store openings, like-for-like sales guidance, CEO comment) MOSCOW, Aug 12 (Reuters) - Russian low-cost retailer Fix Price on Thursday raised its store opening plan for this year after reporting a 28.1% jump in first-half revenue to 106.1 billion roubles ($1.44 billion). The results lifted Fix Price’s shares, which by late July had fallen more than 20% from their London market debut in March, to a more than three-week high. By 1300 GMT, the shares were 2.3% higher. Fix Price raised around $2 billion in the March initial public offering (IPO), the biggest Russian IPO since Western sanctions were introduced in 2014, capitalising on the COVID-19 pandemic reducing Russians’ spending power, which boosted footfall at lower-cost retailers. Fix Price, which sells in stores and online, said the revenue jump was driven by its 18th consecutive quarter of double-digit like-for-like sales growth along with the expansion of its network by 418 stores in the first half of the year. Like-for-like sales grew 11.9% and are expected to increase 10% across 2021, while the company now aims to open around 730 stores this year, up from 700 previously. Fix Price should gain from state support for families with children, ordered by President Vladimir Putin ahead of parliamentary elections in September, ITI Capital analysts said. Earnings before interest, tax, depreciation and amortisation (EBITDA) increased 24.1% to 19.8 billion roubles, with an EBITDA margin of 18.7%, down from 19.3% for the same period a year ago. Chief Executive Dmitry Kirsanov said this was a robust EBITDA margin, slightly below the unusually high level of last year and significantly above the same period in pre-COVID 2019. Fix Price said it intended to pay an interim dividend of 11.5 roubles per share or global depositary receipt, amounting to 100% of profit under international financial reporting standards for the first half of 2021. BCS Global Markets analysts said this implied a dividend yield of 2%.