** Vardhman Special Steels VARM.NS surges an exchange-allowed maximum of 20% to 248.9 rupees
** Stock set for biggest one-day pct gain since April 2017, with trading volume 4x the 30-day daily avg
** Alloy steel maker to set up new plant that it says will help lower steelmaking costs, expand product line
** Planned capacity of 500,000 MT per annum of billet production with capex of 20 bln rupees ($234 mln)
** VARM extends YTD gains to ~10%
($1 = 85.4725 Indian rupees)
(Reporting by Anuran Sadhu in Bengaluru)
((Anuran.Sadhu@thomsonreuters.com; +91 8697274436;))